The Moral Character of Cryptographic Work?
Phillip Rogaway
Department of Computer Science
University of California, Davis, USA
rogaway@cs.ucdavis.edu
December 2015
(minor revisions March 2016)

Abstract. Cryptography rearranges power: it configures who can dowhat, from what. This makes cryptography an inherently political tool,and it confers on the field an intrinsically moral dimension. The Snowden
revelations motivate a reassessment of the political and moral positioningof cryptography. They lead one to ask if our inability to effectively
address mass surveillance constitutes a failure of our field. I believe thatit does. I call for a community-wide effort to develop more effective means
to resist mass surveillance. I plead for a reinvention of our disciplinary
culture to attend not only to puzzles and math, but, also, to the societal
implications of our work.
Keywords: cryptography · ethics · mass surveillance · privacy ·Snowden · social responsibility

Preamble. Most academic cryptographers seem to think that our field is a fun,deep, and politically neutral game—a set of puzzles involving communicating
parties and notional adversaries. This vision of who we are animates a field
whose work is intellectually impressive and rapidly produced, but also quite
inbred and divorced from real-world concerns. Is this what cryptography should
be like? Is it how we should expend the bulk of our intellectual capital?
For me, these questions came to a head with the Snowden disclosures of 2013.
If cryptography’s most basic aim is to enable secure communications, how could
it not be a colossal failure of our field when ordinary people lack even a modicumof communication privacy when interacting electronically? Yet I soon realizedthat most cryptographers didn’t see it this way. Most seemed to feel that thedisclosures didn’t even implicate us cryptographers.
I think that they do. So I want to talk about the moral obligations of cryptographers, and my community as a whole. This is not a topic cryptographersroutinely discuss. In this post-Snowden era, I think it needs to be.
?

This is an essay written to accompany an invited talk (the 2015 IACR Distinguished
Lecture) given at Asiacrypt 2015 on December 2, 2015, in Auckland, New Zealand.
The essay and talk are addressed to the cryptographic community—my community—
and the words “we” and “our” should be so interpreted. I apologize in advance if I
offend anyone with any of my comments; nothing of the sort is my intent.

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P. Rogaway

Part 1: Social responsibility of scientists and engineers
A famous manifesto. I’d like to begin with a story—a true story.1 To set thestage, it is London, the summer of 1955. A roomful of reporters have assembled
for a press conference in Caxton Hall, a red brick building in Westminister. The
media have been summoned in a plan hatched by Bertrand Russell, with somehelp from the editor of The Observer newspaper. The reporters don’t know just
why they are here, having only been told that a team of the world’s leading
scientists were ready to release something of world-wide significance. The press
knows that Bertrand Russell is involved. With Einstein’s recent death, Russell
has become the world’s most famous living intellectual.
Russell has been in his home, hiding, all week. All day long the phonerings, the doorbell rings. Reporters are trying to find out what is this big
announcement. Russell’s wife and his housekeeper make excuses and shoo thereporters away.
As the press conference begins, the reporters learn from Russell andaccompanying physicist Joseph Rotblat that they have not been assembled
to hear of some new scientific discovery, but to receive a prepared, politicalstatement. It’s a fairly brief statement, but it’s been signed by eleven2 of theworld’s leading scientists—nine of them Nobel laureates. Albert Einstein isamong the signatories, signing just days before he became ill and died.
The document would become known as the Russell–Einstein manifesto.3 I
hope that its contents are known to you. It speaks of the existential threat
to mankind posed by nuclear weapons. It’s final passage sounds desperately
plaintive as Russell writes:
We appeal, as human beings, to human beings: Remember your humanity, andforget the rest. If you can do so, the way lies open to a new Paradise; if you
cannot, there lies before you the risk of universal death.4

The reporters ask questions and soon warm to the manifesto’s importance. The
next day, the manifesto is carried as front-page news of most the world’s major
newspapers. For the next several days, at least, it is the talk of the world.
The Russell–Einstein manifesto galvanized the peace and disarmament
movements. It led to the Pugwash conferences, for which Joseph Rotblat andthe conference-series itself would eventually win the Nobel Peace Prize (1995).
Rotblat credits the manifesto for helping to create the conditions that gave riseto the Nuclear Non-Proliferation Treaty (NPT, 1970).5 In his Nobel Peace Prizeacceptance speech, Rotblat explains:
1

This account is largely taken from Sandra Butcher: The origins of the Russell–
Einstein manifesto. Pugwash Conference on Science and World Affairs, May 2005.
2
At the time of the press conference, Russell had heard from only eight.
3
The name would seem to be an instance of the “Matthew effect,” as signatories Max
Born, Frédéric Joliot-Curie, and Joseph Rotblat all played roles at least as large as
Einstein’s.
4
Quoted in Joseph Rotblat, ed., Proceedings of the First Pugwash Conference on
Science and World Affairs, Pugwash Council, 1982.
5
Butcher, op. cit., Foreword, p. 3.

The Moral Character of Cryptographic Work

3

From my earliest days I had a passion for science. But science, the exercise of
the supreme power of the human intellect, was always linked in my mind with
benefit to people. I saw science as being in harmony with humanity. I did not
imagine that the second half of my life would be spent on efforts to avert amortal danger to humanity created by science.6

Two modes of behaving politically. I begin with the Russell–Einsteinmanifesto to remind you of two things: first, that technical work itself can
implicate politics; and second, that some scientists, in response, do take on
overtly political roles. These two ways to behave politically are different (evenif, to people like Rotblat, they go hand-in-hand). Let’s look at each.
Implicit politics. A scientist engages in what I’ll call implicit politics byinfluencing power relations as a byproduct of technical work. Politics is about
power—who has how much of it, and what sort. The nuclear bomb is the ultimate
expression of coercive power; it is politics incarnate. Had Rotblat shunned every
ostensibly political role in his life, his life’s work would still have been political.
Immensely, if implicitly, so.
But we don’t need the specter of mushroom clouds to be dealing with
politically relevant technology: scientific and technical work routinely implicates
politics. This is an overarching insight from decades of work at the crossroads ofscience, technology, and society.7 Technological ideas and technological things
are not politically neutral: routinely, they have strong, built-in tendencies.
Technological advances are usefully considered not only from the lens of how
they work, but also why they came to be as they did, whom they help, and whomthey harm. Emphasizing the breadth of man’s agency and technological options,and borrowing a beautiful phrase of Borges, it has been said that innovation isa garden of forking paths.8
Still, cryptographic ideas can be quite mathematical; mightn’t this make them
relatively apolitical? Absolutely not. That cryptographic work is deeply tied topolitics is a claim so obvious that only a cryptographer could fail to see it. Thus
I’ll devote considerable time to this claim. But let me first speak of the second
way for scientist to behave politically.
Overt politics. A scientist can engage in overt politics through the mechanismsof activism and participatory democracy. In writing the Russell–Einstein
6

Joseph Rotblat, “Remember Your Humanity.” Acceptance and Nobel lecture, 1995.
Text available at Nobelprize.org
7
The literature in this direction is too vast to possibly survey. University programs inthis space often go by the acronym STS, for science and technology studies or science,technology, and society. The work of Langdon Winner is particularly concerned withthe relation between technological artifacts and their implicit political dimension.
8
The quote is from: Robin Williams and David Edge: The social shaping of technology.
Research Policy (25), 865–899, Elsevier Science B.V., (1966). The implicit reference
is to the eerie Borges short story “El jardı́n de senderos que se bifurcan” (The Gardenof Forking Paths) (1941).

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P. Rogaway

manifesto and in rolling it out the way he did, Russell was working masterfully inthis domain. Russell was not only a mathematician: he had broad contributions
across philosophy, had won the Nobel prize in literature, and was a well-known
social critic and anti-war activist.
The ethic of responsibility. Bertrand Russell’s breadth was extraordinary.
But the mere existence of the politically engaged intellectual doesn’t suggest that
this pairing is at all representative. To what extent are scientists and engineerssocially engaged? And to what extent do societal norms demand that they be?9
Nowadays, an ethic of responsibility is preached in university courses andadvocated by professional organizations. It is the doctrinal view. The putative
norm contends that scientists and engineers have an obligation to select workthat promotes the social good (a positive right), or, at the very least, to refrainfrom work that damages mankind or the environment (a negative right).10 The
obligation stems from three basic truths: that the work of scientists and engineerstransforms society; that this transformation can be for the better or for the worse;and that what we do is arcane enough that we bring an essential perspective to
public discourse. The socially engaged scientist is expected to bring a normative
vision for how work in his or her field should impact society. He or she aims tosteer things in that direction.
To be sure, decision making under the ethic of responsibility is not easy. It
can be impossible to foresee if a line of work is going to be used for good or for ill.
Additionally, the for-good-or-for-ill dichotomy can be simplistic and subjective tothe point of meaninglessness. Still, despite such difficulties, the socially engaged
scientist is supposed to investigate, think, and decide what work he will or will
not do, and what organizations he will or will not work for. The judgment should
be made without over-valuing one’s own self-interest.
Historical events shaping the ethic of responsibility. The ascendancy ofthe ethic of responsibility was shaped by three historical events of World War 2
and its aftermath.
1. The first, already touched on, was the experience of the atomic scientists.
After the war, with science left in a position both revered and feared, prominent
physicists became public figures. Some became outspoken in their advocacy forpeace, or their opposition to further weapons development. Recall the widespread
concerns from physicists to Reagan’s Strategic Defense Initiative (SDI)11 orHans Bethe’s famous letter to Bill Clinton where he argued against another9

Some of my comments in the remainder of this section were informed by Matthew
Wisnioski: Engineers for Change: Competing Visions of Technology in 1960s
America. MIT Press, 2012.
10
While these two possibilities are very different, distinguishing between them will not
be important for the discussion of this essay.
11
The debate within the scientific community got significant media attention following
release of a book-length study from the American Physical Society (APS) Study
Group (N. Bloembergen, C. K. Patel, cochairmen), Report to The American PhysicalSociety of the Study Group on Science and Technology of Directed Energy Weapons,

The Moral Character of Cryptographic Work5round of U.S. nuclear-weapons development.12 A willingness to speak truth topower 13 became a tradition among physicists—one that, I think, continues toshape physicists’ identity.14
As an example, recall the pepper-spray incident of 2011 at my own campus,
the University of California, Davis.15 Carrying out the Chancellor’s instructions
to clear “Occupy” protesters, police officer John Pike pepper-sprayed students
who sat, arms linked, on the university’s central quad. Videos of the event went
viral,16 while memes of Officer Pike casually pepper-spraying anything became
a second Internet sensation. But the observation I’d like to make is that, in theaftermath of the incident, the only UCD department outside the humanities tocondemn the Chancellor or call for her resignation was Physics.17 The Chancellor
was mystified. She understood the strong reaction from our (underfunded andpolitically liberal) English department, but she didn’t anticipate complaints
from a (well-funded and generally conservative) Physics department.18 What
the Chancellor might not have internalized is that physicists retain a post-war
legacy not only of snuggling up close to power, but also of nipping at its ankles.
2. A second historical event that helped shape the post-war view ofmoral responsibility was the Nuremberg trials (1945–1946). While the defense
repeatedly proffered that the accused were simply following orders, this view
was almost universally rejected : following orders did not efface legal or moral
culpability. The Nuremberg trials began with the Medical Case, the prosecutionof 23 scientists, physicians, and other senior officials for gruesome and routinely
fatal medical experiments on prisoners.19
APS, New York (April 1987). The debate was not one-sided: many physicists
supported SDI, and many felt the APS study to be too negative or too political.
12
See http://fas.org/bethecr.htm#letter for Bethe’s 1997 letter.
13
The well-known expression comes from a pamphlet “Speak truth to power: a Quakersearch for an alternative to violence,” 1955. http://www.quaker.org/sttp.html
14
Of course not every prominent physicist was oppositional. Edward Teller famously
championed the development of fusion bombs and SDI. These positions were divisive,with some of Teller’s peers seeing him as irresponsible, jingoistic, or insane.
15
The definitive report on the incident is: Reynoso, C., Blando, P., Bush, T., Herbert,P., McKenna, W., Rauchway, E., Balcklock, P., Brownstein, A., Dooley, D., Kolesar,
K., Penny, C., Sterline, R., Sakaki, J.: UC Davis Nov. 18, 2011 “Pepper Spray
Incident” Task Force Report: The Reynoso Task Force Report. (March 2012)
Available at http://www.ucsf.edu/sites/default/files/legacy files/reynoso-report.pdf(visited 2015.08.07)
16
There are 2 million views of https://www.youtube.com/watch?v=6AdDLhPwpp4
17
Nathan Brown: Op-ed: Reviewing the case for Katehi’s resignation. Davis Enterprisenewspaper (Dec. 18, 2011). UC Davis Physics Department, untitled press release(Nov. 22, 2011), available at http://tinyurl.com/ucd-physics-pepper-spray (lastvisited 2015.08.07).
18
The Chancellor expressed this sentiment in a meeting between her and interested
faculty of the College of Engineering (date unknown, probably early 2012).
19
See, for example, Israel Gutman: Encyclopedia of the Holocaust, Macmillan Library
Reference USA, 1990, entries: “Medical Experiments” by Nava Cohen, pp. 957–966,
and “Physicians, Nazi” by Robert Jay Lifton and Amy Hackett, pp. 1127–1132.

6

P. Rogaway

Years later, as though in sequel, the world would watch in nervous fascination
the trial of Adolf Eichmann (1961). Hannah Arendt’s controversial portrayalof Eichmann would come to be formative in shaping our understanding ofwhat, ethically, had transpired during the Holocaust. She wrote of the utter
ordinariness of the man.20 Arendt’s book on the trial, memorably subtitled The
Banality of Evil, would be published the same year (1963) as Stanley Milgram’sclassical experiments on obedience, where Milgram produced the stunning (andwidely repeated) finding that a large fraction of volunteers would follow a whitecoated scientist’s gentle urging to deliver apparently life-threatening shocks tosomeone they thought was a fellow test subject.21
3. Finally, I would mention the rise of the environmental movement as
contributing to the rise of an ethic of responsibility. While environmentalism
dates to the mid-nineteenth century and before, as a significant social movement,
the 1962 publication of Rachel Carson’s Silent Spring is a milestone. Her bookpainted a picture of the end of life not by the drama of nuclear warfare, but
the disappearance of songbirds, silenced by the routine if oversized activities ofchemical manufacturing and non-specific pesticides.
The good scientist. The three experiences I have just described implied ademocratization of responsibility. Scientists had to assume responsibility for what
they did, for technology would take us to a very dark place if they did not.
Stripped of ethical restraint, science would bring a world of nightmare bombs,
gas chambers, and macabre human experiments. It would bring a dying, poisoned
world.
And so, in the decades following the war, the ethic of responsibility became—at least rhetorically—the doctrinal norm. Increasing numbers of scientists andengineers, as well as their professional organizations, began to engage on
issues of social responsibility. The Pugwash Conferences began in 1955. The
National Society of Professional Engineers adopted a code of ethics in 1964
that gave primacy to social responsibility. As its first imperative, the codesays that “Engineers, in the fulfillment of their professional duties, shall holdparamount the safety, health, and welfare of the public.” Similar language
would spread across other codes of ethics, including those of the ACM andIEEE.22 The Union of Concerned Scientists was formed at MIT in 1969—thesame year a work stoppage at MIT, coordinated with 30 other universities,
enjoyed substantial student, faculty, and administrative support. It called fora realignment of research directions away from military pursuits and towards
human needs. Computer Professionals for Social Responsibility (CPSR) began
20

Hannah Arendt: Eichmann in Jerusalem: A Report on the Banality of Evil. Viking
Adult (1963)
21
Stanley Milgram: Behavioral study of obedience. Journal of Abnormal and Social
Psychology, 67(4), pp. 371–378 (1963).
22
In the US, only mining engineers failed to adopt a code of ethics, according toWikipedia article “Engineering ethics.”

The Moral Character of Cryptographic Work7

its work opposing the SDI in 1983.23 That same year, the IACR was founded, its
self-described mission not only to advance the theory and practice of cryptology
but also, lest we forget, to serve the public welfare.24 The Electronic Frontier
Foundation (EFF) and Privacy International (PI) were both formed in 1990, andbecame effective advocates in such matters as the defeat of the Clipper Chip.
All of this is but a sampling of the overt politics from scientists and engineers.
Against this backdrop, the figure of the brilliant but humane scientist becamea cultural motif. Jonas Salk had wiped out polio. Einstein became a cultural icon,
one unfazed by the inconvenience of his death. The image of him sticking out his
tongue may be the most widely recognizable photograph of any scientist, ever.
Richard Feynman would be painted in equally colorful ways, the no-nonsense
genius pounding on bongo drums and shoving black rubbery stuff into ice water.
Gene Roddenberry’s Star Trek imagined a future that featured the scientist–
humanist–hero as one team, if not one individual. Carl Sagan, speaking gently
to the camera in episodes of Cosmos (1980), seemed the real-life embodiment of
this aspirational package.
The ethic of responsibility in decline. And yet, for all I have said, thescientist or engineer seriously concerned about the social impact of his workis, I think, so rare as to be nearly a matter of myth. Never during the cold
war, nor in any of the subsequent US wars, did US companies have difficulty
recruiting or retaining the hundreds of thousands of scientists and engineers
engaged in building weapons systems.25 Universities like my own were happy to
add their support; the University of California would, for decades, run the USA’s
nuclear weapons design laboratories.26 In nearly 20 years advising students at myuniversity, I have observed that a wish for right livelihood 27 almost never figures
into the employment decisions of undergraduate computer science students. And
this isn’t unique to computer scientists: of the five most highly ranked websites
I found on a Google search of deciding among job offers, not one suggests
considering the institutional goals of the employer or the social worth of what
they do.28
23

The organization dissolved in 2013.
Article II of the Bylaws of the International Association for Cryptologic Research:“The purposes of the IACR are to advance the theory and practice of cryptology
and related fields, and to promote the interests of its members with respect
thereto, and to serve the public welfare.” Last revised Nov. 18, 2013. Availableat www.iacr.org/docs/bylaws.pdf
25
See, for example, Thomas P. Hughes: Rescuing Prometheus, 1998 (on the Atlas
project).
26
Following some security breaches, they now do this in partnership withindustry, particularly with Bechtel. See http://www.bechtel.com/projects/usnational-laboratories/
27
The term is associated to Buddhism, right livelihood being one of the virtues of the
Noble Eightfold Path.
28
My top five Google search results to “deciding among job offers” (no quotes)
on Aug 26, 2015 were: (1) “Help! How Do I Choose Between Two Job Of24

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P. Rogaway

Nowadays I ask computer-science faculty candidates to explain their view on
the ethical responsibilities of computer scientists. Some respond like a deer inheadlights, unsure what such a question could even mean. One recent faculty
candidate, a data-mining researcher whose work seemed a compendium of DoDfunded projects for socially reprehensible aims, admitted that she felt no social
responsibility. “I am a body without a soul,” she earnestly explained. It was
sincere—and creepy.
Stanley Fish, a well-known literary theorist, professor, and dean, admonishes
faculty not to pursue research programs rooted in values. (His 2012 book is titled
Save the World on Your Own Time.) Fish advises professors to
do your job; don’t try to do someone else’s job . . .; and don’t let anyone else
do your job. In other words, don’t confuse your academic obligations with the
obligation to save the world; that’s not your job as an academic . . .
Marx famously said that our job is not to interpret the world, but to change
it. In the academy, however, it is exactly the reverse: our job is not to change
the world, but to interpret it.29

Perhaps such amorality, however revolting, is harmless in Fish’s intellectual
realm: one doesn’t particularly expect literary theory to change the world. But
scientists and engineers do just that. A refusal to direct the change we do isboth morally bankrupt and ingracious. Our work as academics, we should neverforget, is subsidized by society.30
So far I have not said why the post-war ethic-of-responsibility didn’t catch on.
I could give multiple answers, starting with the rise of radical individualism.31
But I prefer to focus on something else: extreme technological optimism.
fers.” CareerCast website, www.careercast.com/career-news/help-how-do-i-choosebetween-two-job-offers. (2) “4 questions to help you decide between job offers.”
Natalie Wearstler, Sep. 16, 2013. theweek.com/articles/460019/4-questions-helpdecide-between-job-offers. (3) “You Got the Jobs! How to Decide Between Offers.”
Forbes, June 6, 2011. www.forbes.com/sites/prettyyoungprofessional/2011/06/06/
you-got-the-jobs-how-to-decide-between-offers/. (4) “6 Secrets to Choosing Between
Job Offers.” July 31, 2013. www.aegistech.com/how-to-choose-between-multiplejob-offers/. (5) “How to Choose Between Multiple Job Offers.” Sam Tomarchio,
Aegistech. www.aegistech.com/how-to-choose-between-multiple-job-offers/. The indicated websites do not contain the words ethics, moral, or social, nor any
comments concerning the ethical character or social value of one’s work. The author
acknowledges that Google search results are not reproducible.
29
Stanley Fish: Why we built the ivory tower. NY Times, Opinion Section, May 21,
2004.
30
Elisabeth Pain: The social responsibility of scientists. Career Magazine of Science,
Feb. 16, 2013. Report on the 2013 AAAS meeting and, in particular, the comments ofMark Frankel. The speaker asks listeners, especially graduate students, to keep firmly
in mind that scientific research is a social institution, and one that is subsidized bysociety.
31
Radical individualism is the belief that one’s personal interests are more important
than those of society. It is well captured by the “Greed is Good” speech from
Oliver Stone’s “Wall Street” (1987), although what the individual cares about canbe something other than personal wealth.

The Moral Character of Cryptographic Work

9Technological optimism. Technological optimists believe that technology
makes life better. According to this view, we live longer, have more freedom,
enjoy more leisure. Technology enriches us with artifacts, knowledge, andpotential. Coupled with capitalism, technology has become this extraordinary
tool for human development. At this point, it is central to mankind’s mission.
While technology does bring some unintended consequences, innovation itself
will see us through.
Technological optimism animates everyone from school children to Turing
Award winners. Accepting his 2012 Turing Award, Silvio Micali, said that
Computer science is marking an epical change in human history. We areconquering a new and vast scientific continent. . . . Virtually all areas of humanactivity . . . [and] virtually all areas of human knowledge . . . are benefiting fromour conceptual and technical contributions. . . . Long live computer science!32

If you’re a technological optimist, a rosy future flows from the wellspringof your work. This implies a limitation on ethical responsibility. The important
thing is to do the work, and do it well. This even becomes a moral imperative,
as the work itself is your social contribution.
But what if computer science is not benefiting man? Technological pessimists
like Jacques Ellul, Herbert Marcuse, and Lewis Mumford certainly didn’t thinkthat it was. They saw modern technology as an interlocking, out-of-control
system that, instead of fulfilling human needs, engendered pointless wants anddeadlier weapons. Man is becoming little more than the sex organs of the machine
world.33
Taking a less “extreme” view,34 technological contextualists35 acknowledge
the concerns of the pessimists, but emphasize man’s essential agency and the32

Silvio Micali, ACM Turing Award Acceptance speech. ACM awards ceremony, San
Francisco, June 15, 2013. https://www.youtube.com/watch?v=W0N4WnjGHwQ.
Ending his speech with a cheer, there is, perhaps, an element of facetiousness inSilvio’s unbridled optimism. Yet over-the-top optimism seems endemic to discourseon computer science.
The awards ceremony took place a little over a week after the first news story basedon a Snowden document (June 6, 2013). But the threat of computing technology was
not to be acknowledged, only its promise praised.
33
Marshal McLuhan, Understanding Media: The Extensions of Man, McGraw-Hill,
1964: “Man becomes, as it were, the sex organs of the machine world, as the bee ofthe plant world, enabling it to fecundate and evolve ever new forms.”
34
To be clear, I do not think there’s anything extreme in the views of prominenttechnological pessimists; if anything, prevailing optimistic views seems to me far lessreasoned and more extreme.
35This is the phrase used by Ian Barbour: Ethics in an Age of Technology: The Gifford
Lectures, Volume Two), HarperCollins (1993), which contains a good descriptionof the writings of the contextualists (which include the author himself). Langdon
Winner speaks of an ideology of technological politics for roughly the same concept
as contextualism; see Autonomous Technology: Technics-out-of-Control as a Themein Political Thought. MIT Press, 1977.

10

P. Rogaway

malleability of technology. Contextualism dominates the dialectic of technology
studies.
The ethic of responsibility is always paired with the contextualist view ofsociotechnology. At some level, this must be so: a normative need vanishes if, in
the garden of forking paths, all paths lead to good (or, for that matter, to bad).
But it is technological optimism that most people buy into, especially scientists
and engineers. And unbridled technological optimism undermines the basic needfor social responsibility.
Conclusion to part 1. Ultimately, I think the post-war turn towards social
responsibility in science and engineering was less a turn than a sideways glance.
While the rhetoric of responsibility would provide cover from technology’s critics,
few scientists or engineers would ever come to internalize that their work
embodied socially relevant values. If researchers like us were actually supposed
to know or care about this stuff in any operationally significant way, well, I think
we didn’t get the memo.
So let me retransmit it. It says that your moral duties extend beyond theimperative that you personally do no harm: you have to try to promote the social
good, too. Also, it says that your moral duties stem not just from your stature
as a moral individual, but, also, from the professional communities to which you
belong: cryptographer, computer scientist, scientist, technologist.
With few exceptions, the atomic scientists who worked on disarmament
were not the same individuals as those who built the bomb. Their colleagues—
fellow physicists—did that. Cryptographers didn’t turn the Internet into an
instrument of total surveillance, but our colleagues—fellow computer scientists
and engineers—did that. And cryptographers have some capacity to help.
But you will only believe that claim if you recognize that cryptography can
influence power relations. I suspect that many of you see no real connection
between social, political, and ethical values and what you work on. You don’t
build bombs, experiment on people, or destroy the environment. You don’t spy
on populations. You hack math and write papers. This doesn’t sound ethicallyladen. I want to show you that it is.

Part 2: The political character of cryptographic work
Scientist or spy? There’s an irony in discussing the claim that cryptographic
work is political, and it is this: to someone unconnected to the field, and also
to the crypto-hobbyist, the claim may seem obviously true. But to the young
researcher who spends his life writing papers in cryptography, the claim mayseem just as obviously false. What gives?
The outsider’s view of cryptography might be based on cinematic portrayals.
Films like Sneakers (1992), Pi (1998), A Beautiful Mind (2001), Enigma (2001),
Traveling Salesman (2012), Citizenfour (2014), and The Imitation Game (2014)
depict cryptography as a field intertwined with politics. Cryptographers are thebrilliant and handsome mathematicians that power needs to have working on its

The Moral Character of Cryptographic Work11

side. We are, I am happy to report, heroic geniuses. A little crazy, to be sure,but that just adds to the luster.
Similarly, the crypto hobbyist may have read historical accounts dealing withcryptography, like the books of James Bamford or David Kahn.36 Such accounts
demonstrate that, historically, cryptography is about power. It’s a realm inwhich governments spend enormous sums of money,37 and maybe not unwisely:
the work shapes the outcome of wars, and undergirds diplomatic and economic
maneuvering.38
Yet no academic cryptographer would confuse historical or fictional accountsof cryptography with what we actually do. Our discipline investigates academic
problems that fall within our disciplinary boundaries. Pick up a Springer
proceedings or browse ePrint papers and our field looks utterly non-political.
If power is anywhere in the picture, it is in the abstract capacities of notional
adversaries39 or, in a different branch of our field, the power expenditure,measured in watts, for some hardware. We work on problems that strike us asinteresting or scientifically important. We’re not aiming to advance the interestsof anything but science itself (or, perhaps, one’s own career).
So distinct claims about cryptography’s connectedness to power stem, at leastin part, from radically different archetypes of what the cryptographer is: scientist
or spy. The NSA/GCHQ employee who hacks Gemalto to implant malware andsteal SIM keys40 is just as deserving of being called a “cryptographer” as the
MIT-trained theorist who devises a new approach for functional encryption.
Both are dealing in questions of privacy, communications, adversaries, and clevertechniques, and we would do well to emphasize these commonalities if we want
to see our disciplinary universe in context or nudge it towards greater relevance.
Academic cryptography used to be more political. The ascendance ofa new cryptographer archetype—the academic cryptographer—fails to really36

The series of books by James Bamford on the history of the NSA are The Puzzle
Palace: A Report on America’s Most Secret Agency (1982), Body of Secrets:
Anatomy of the Ultra-Secret National Security Agency (2001), and The Shadow
Factory: The NSA from 9/11 to the Eavesdropping on America (2008). The classic
book of David Kahn on the history of code breaking is The Codebreakers: The Storyof Secret Writing (1967).
37
The U.S. “Consolidated Cryptologic Program” includes about 35,000 employees.
NSA budget for 2013 was $10.3 billion, with $1 billion of this marked
as “cryptanalysis and exploitation services” and $429 million “research andtechnology.” intelligence operations between 2004–2013. See Barton Gellman andGreg Miller, ‘Black budget’ summary details U.S. spy network’s successes, failures,and objectives; The Washington Post, April 29, 2013.
38
For an account of the extreme utility of surveillance and cryptography in recent U.S.
wars, see Shane Harris: @War: The Rise of the Military-Internet Complex. Eamon
Dolan/Houghton Mifflin Harcourt (2014).
39
For example, the phrase “an all-powerful adversary” is usually meant as an agent
having no computational restrictions, but which conforms to a specified model.
40
Jeremy Scahill and Josh Begley: The great SIM heist: how spies stole the keys tothe encryption castle. The Intercept, Feb. 19, 2015.

12

P. Rogaway

explain our politically detached posture. For one thing, academic cryptographers
were once more concerned with our field’s sociopolitical dimensions. Some evencame to cryptography for such reasons. Consider, for example, this fragment of
Whit Diffie’s testimony at the Newegg trial. Speaking of his wife, Diffie says:
I told her that we were headed into a world where people would have important,intimate, long-term relationships with people they had never met face to face.
I was worried about privacy in that world, and that’s why I was working on
cryptography.41

Diffie and his advisor, Martin Hellman, have long evinced a concern forsociopolitical problems touching technology. You see it in their criticism of DES’s
key length,42 in Hellman’s activism on nuclear disarmament,43 in Diffie’s bookon the politics of wiretapping with Susan Landau,44 and in his co-invention of
forward secrecy.45 You see it in the New Directions paper:46 when the authors
boldly begin “We stand today on the brink of a revolution in cryptography,” theanticipated revolution was not, at least primarily, the theory community bringing
forth mind-altering notions of provable security, simulatability, or multiparty
computation.47 The authors were interested in technological changes that weretranspiring, and concomitant social opportunities and needs.48
Still more ostensibly political is David Chaum’s body of scientific work,
which thoroughly embeds concerns for democracy and individual autonomy.
41

Joe Mulllin: Newegg trial: crypto legend takes the stand, goes for knockout patentpunch. Ars Technica, Nov. 24, 2013.
42
Whitfield Diffie and Martin Hellman: Exhaustive cryptanalysis of the NBS Data
Encryption Standard. Computer 10(6), pp. 74–84 (1977).
43
See, for example: Anatoly Gromyko and Martin Hellman: Breakthrough: Emerging
New Thinking: Soviet and Western Scholars Issue a Challenge to Build a World
Beyond War, 1988.
44
Whitfield Diffie and Susan Landau: Privacy on the Line: The Politics of Wiretappingand Encryption, MIT Press (2007).
45
Whitfield Diffie, Paul van Oorschot, Michael Wiener: Authentication andauthenticated key exchanges. Designs, Codes and Cryptography, 2(2), pp. 107–125(1992).
46
Whitfield Diffie and Martin Hellman: New directions in cryptography. IEEE
Transactions on Information Theory, 22(6), pp. 644-654 (1976).
47
Yet the authors did seem to anticipate such a possibility: “At the same time,
theoretical developments in information theory and computer science show promiseof providing provably secure cryptosystems, changing this ancient art into a science.”
Ibid., p. 29.
48
They write, for example, that “The development of cheap digital hardware has freed
it [cryptography] from the design limitations of mechanical computing and brought
the cost of high grade cryptographic devices down to where they can be used in suchcommercial applications as remote cash dispensers and computer terminals. . . . The
development of computer controlled communication networks promises effortless andinexpensive contact between people or computers on opposite sides of the world . . ..”Ibid, p. 29.

The Moral Character of Cryptographic Work

13

Chaum’s 1981 paper49 Untraceable Electronic Mail, Return Addresses, andDigital Pseudonyms, [Chaum81], suggests that a crucial privacy goal whensending an email is to hide who is communicating with whom. The metadata, inmodern political parlance. The author offered mix nets for a solution.50
Chaum would go on to provide the founding ideas for anonymous electronic
cash and electronic voting. His papers would routinely draw on overtly politicalmotivations.51 In a recent conversation, Chaum expressed surprise at the extent
to which academics gravitated to a field—cryptography—so connected to issuesof power.52
Stripping out the politics. But as academics gravitated to cryptography, theytended to sanitize it, stripping it of ostensible connectedness to power. Appliedand privacy-related work drifted outside of the field’s core venues, the IACR
conferences. It is as though a chemical synthesis would take place, transforming
this powerful powder into harmless dust.
Consider that there is now a conference named “Real World Cryptography”(RWC).53 There is humor—but maybe gallows humor—that a field with a genesis
and capability as real-world as ours should find reason to create a venue so
49

The paper appears in Communications of the ACM (CACM), 24(2), pp. 84–88(1981).
50
In a nutshell, a mix net works like this. Each user’s communications will pass througha series of routers. (For the approach to add value, these routers, or mixes, shouldhave diversity in administrative control, jurisdictional control, or the code they run.)
Plaintexts will be multiply encrypted, using one key for each router in the series.
Each router will peel off one layer of encryption. Before passing the result to thenext router, it will wait until it has some number of outgoing messages, and thenreorder them. An adversary who observes network traffic—even one who controls
some subset of the routers—should be unable to identify who has sent what towhom.
51
For example: “The foundation is being laid for a dossier society, in which computers
could be used to infer individuals’ life-styles, habits, whereabouts, and associations
from data collected in ordinary consumer transactions. Uncertainty about whether
data will remain secure against abuse by those maintaining or tapping it can havea ‘chilling effect,’ causing people to alter their observable activities.” David Chaum:
Security without identification: transaction systems to make big brother obsolete.
Communications of the ACM (CACM), 28(10), pp. 1030–1044, 1985.
52
Speaking of cryptography, Chaum told me “I’ve been aware from the beginning of the
field, that it was a powerful field, and would become more and more as information
technology advanced. I was surprised that academics were as interested as they werein cryptography, because it was an area so connected to power.” Conversation withDavid Chaum, 17 Aug 2015. Santa Barbara, California.
53
Starting in 2012, this annual event already attracts more attendees than Crypto.
RWC’s steering committee is Dan Boneh, Aggelos Kiayias, Brian LaMacchia,
Kenny Paterson, Tom Ristenpart, Tom Shrimpton, and Nigel Smart. Webpage
http://www.realworldcrypto.com/ explains: “This annual conference aims to bring
together cryptography researchers with developers implementing cryptography inreal-world systems. The conference goal is to strengthen the dialog between these

14

P. Rogaway

named.54 Ask a colleague in Graphics or Cloud Computing how it would fly intheir community if someone started a conference called Real World Computer
Graphics (RWCG 2015) or Real World Cloud Computing (RWCC 2016). They
will laugh.
An especially problematic excision of the political is the marginalization
within the cryptographic community of the secure-messaging problem,55 an
instance of which was the problem addressed by [Chaum81]. Secure-messaging
is the most fundamental privacy problem in cryptography: how can parties
communicate in such a way that nobody knows who said what. More than adecade after the problem was introduced, Rackoff and Simon would comment on
the near-absence of attention being paid to the it.56 Another 20-plus years later,
the situation is this: there is now a mountain of work on secure-messaging, but
it’s unclear what most of it actually does. A recent systemization-of-knowledge
article57 paints a picture of a cryptographic task enjoying a flourishing of ad hoc
solutions, but little of it arising from the cryptographic community, as narrowly
construed, or tied to much theory.58 While one could certainly claim that this istrue for almost all practical security goals that employ cryptography, I think thecase is different for secure-messaging: here the work feels almost intentionally
pushed aside.

two communities. Topics covered focus on uses of cryptography in real-world
environments such as the Internet, the cloud, and embedded devices.”
54
Some theorists might take offense by an implication that cryptographic theory is
not “real world,” suggesting that those who do theory must be studying something
unreal, or not of this world (the vapors of poltergeists?). The implicit dichotomiesof cryptographic theory vs. cryptographic practice, real-world and its complement(whatever that might be), would not survive a critical assessment. Yet discourse on
what communities do seems unavoidably full of capricious boundaries.
55
Tellingly, the problem lacks even a widely recognized name. The version of the securemessaging problem Chaum was interested in is a high-latency, public-key version.
56
Charles Rackoff and Daniel Simon: Cryptographic defense against traffic analysis.
STOC ’93, pp. 672–681. The quote is from pp. 672–673.
57
Nik Unger, Sergej Dechand, Joseph Bonneau, Sascha Fahl, Henning Perl, Ian
Goldberg, Matthew Smith: SoK: Secure messaging. IEEE Symposium on Security
and Privacy 2015, pp. 232–249.
58
Little, but not none. See, for example: Nik Unger and Ian Goldberg: Deniable
key exchanges for secure messaging. ACM CCS 2015. N. Borisov, I. Goldberg,
and E. Brewer: Off-the-Record communication, or, why not to use PGP. Privacyin the Electronic Society, pp. 77-84, 2004. Ron Berman, Amos Fiat, Marcin
Gomulkiewicz, Marek Klonowski, Miroslaw Kutylowski, Tomer Levinboim, Amnon
Ta-Shma: Provable unlinkability against traffic analysis with low message overhead.
J. of Cryptology, 28(3), pp. 623–640, 2015. Jan Camenisch and Anna Lysyanskaya:
A formal treatment of onion routing. CRYPTO 2005. Joan Feigenbaum, Aaron
Johnson, and Paul F. Syverson: Probabilistic analysis of onion routing in a black-box
model. ACM Transactions on Information and System Security (TISSEC), 15(3),2012.

The Moral Character of Cryptographic Work

15Children of [Chaum81] and [GM82]. Why would I make such a claim?
An illuminating case study is provided by comparing the venues of the mostcited papers citing [Chaum81] and [GM82], Goldwasser and Micali’s Probabilistic
Encryption.59 The two papers appeared around the same time and havecomparable citation counts.60
The [GM82] paper put forward the definitionally centered, reduction-based
approach to dealing with cryptographic problems. It became a seminal workof the cryptographic community. The most cited papers that cite it appear in
Crypto and Eurocrypt, FOCS, STOC, and ACM CCS.61 The [Chaum81] paper
put forward the secure email problem and suggested a solution. This paper would
be just as seminal—but in spawning work mostly outside the core cryptographic
community. The ten most cited papers that cite Chaum’s paper appear in venues
that, mostly, I had never heard of. Venues not crypto-focused, like MobiSys and
SIGOPS. In fact, the venues for the ten most cited papers citing [GM82] and thevenues for the ten most cited papers citing [Chaum81] have void intersection. I
find this fairly remarkable. It reflects a research community split into fragmentsthat include a GM-derived one and a Chaum-derived one, the second fragment
not really being a part of the cryptographic community at all.62
Why did this fragmentation occur? The most obvious explanation has
to do with rigor: [GM82] offered a mathematically precise approach to its
subject, while [Chaum81] did not. So a partitioning might seem to make sense:
cryptographic work that can be mathematically formal goes to the right; ad hoc
stuff, over to the left.
The problem with this explanation is that it’s wrong. The [Chaum81] paper
supports rigor just fine. Indeed provable security would eventually catch up to
mix nets, although the first definition would take more than 20 years to appear(2003), in a paper by Abe and Imai.63 That the [Chaum81] paper itself didn’t
59

Chaum, op. cit. Shafi Goldwasser and Silvio Micali: Probabilistic encryption and how
to play mental poker keeping secret all partial information. STOC 1982, pp. 365–377. Journal version as: Probabilistic encryption, Journal of Computer and System
Science (JCSS), 28(2), pp. 270–299, April 1984.
60
According to Google scholar: 4481 citations to the Chaum paper, and 3818 citations
for the Goldwasser-Micali paper (both versions, combined). Data as of Oct 14, 2015.
61
The one outlier is a paper by Perrig, Szewczyk, Tygar, Wen, and Culler in MobiCom.
62
In greater detail, the ten most cited [GM82] (both versions combined) appeared at
CCS, Crypto 3×, Eurocrypt, FOCS (2×) MobiCom, STOC (2×). Only MobiCom
is an “unexpected” venue. The ten most cited [Chaum81]-citing papers appeared at
ACM Comp. Surveys, ACM J. of Wireless Networks, ACM MobiSys, ACM Tran.
on Inf. Sys., ACM SIGOPS, IEEE SAC, Proc. of the IEEE USENIX Security
Symposium, and workshops named IPTPS and Designing Privacy Enhancing
Technologies. None of these ten venues is crypto-focused.
63
Masayuki Abe and Hideki Imai: Flaws in some robust optimistic mix-nets.
Information Security and Privacy (ACISP), pp. 39–50, 2003. Journal version:
Masayuki Abe and Hideki Imai: Flaws in robust optimistic mix-nets and stronger
security notions. IEICE Trans. on Fundamentals of Electronics, Communications
and Computer Science, vol. E89A, no. 1, pp. 99–105, Jan 2006.

16

P. Rogaway

provide a formal treatment says nothing about the formalizability of the problem
or what communities would later embrace it; after all, Diffie and Hellman’s
paper64 only informally described trapdoor permutations, public-key encryption,and digital signatures, but all would be absorbed into the cryptographic fold.
Now one might well counter that the problem addressed by [Chaum81] is moredifficult to formalize than any of the examples just named. That’s true. But
it’s simpler to formalize than MPC,65 say, which would quickly gain entrée andstature in the cryptographic community—even without definitions or proofs. So,
ultimately, neither formalizability nor complexity goes far to explain why securemessaging has been marginalized.
A better answer (but by no means the only answer) is made obvious bycomparing the introductions to the most-cited papers citing [GM82] and themost-cited papers citing [Chaum81]. Papers citing [GM82] frame problems
scientifically. Authors claim to solve important technical questions. The tone isassertive, with hints of technological optimism. In marked contrast, papers citing[Chaum81] frame problems socio-politically. Authors speak about some social
problem or need. The tone is reserved, and explicitly contextualist views areroutine. One observes the exact same distinction in tone and stated motivations
when comparing survey articles.66
In 2015, I attended PETS (Privacy Enhancing Technologies Symposium) for
the first time. Listening to people in this community interact is a bit like watching
the cryptographic community through a lens that magically inverts most things.
The PETS community attends closely to the values embedded in work. They
care about artifacts that support human values. They aim to serve the usersof those artifacts. They’re deeply concerned with the politics and technology ofsurveillance. Where, after Chaum, did the moral soul of academic cryptography
go? Maybe it moved to PETS.
There is a lesson in all this. Some might think that a community’s focus ismostly determined by the technical character of the topic it aims to study. It isnot. It is extra-scientific considerations that shape what gets treated where.

64

Diffie and Hellman, op. cit.
Multiparty computation. Andrew Chi-Chih Yao: Protocols for secure computations(Extended Abstract). FOCS 1982, pp. 160–164. Oded Goldreich, Silvio Micali,
Avi Wigderson: How to play any mental game or a completeness theorem for
protocols with honest majority. STOC 1987, pp. 218–229. Michael Ben-Or, Shafi
Goldwasser, Avi Wigderson: Completeness theorems for non-cryptographic faulttolerant distributed computation (extended abstract). STOC 1988, pp. 1–10.
David Chaum, Claude Crépeau, Ivan Damgård: Multiparty unconditionally Secure
protocols (extended abstract). STOC 1988, pp. 11–19.
66
For example, compare the opening pages of: Oded Goldreich: Foundations ofcryptography—a primer. Foundations and Trends in Theoretical Computer Science,
1(1), pp. 1–116, 2004. And: George Danezis and Seda Gürses: A critical reviewof 10 years of privacy technology. Proceedings of Surveillance Cultures: A Global
Surveillance Society?, 2010.
65

The Moral Character of Cryptographic Work17

The cypherpunks. Now there is a group that has long worked at the nexusof cryptography and politics: the cypherpunks.67 The cypherpunks emerged in
the late 1980’s, unified by a mailing list and some overlapping values. The core
belief is that cryptography can be a key tool for protecting individual autonomy
threatened by power.68
The cypherpunks believed that a key question of our age was whether stateand corporate interests would eviscerate liberty through electronic surveillance
and its consequences, or if, instead, people would protect themselves through theartful use of cryptography. The cypherpunks did not seek a world of universal
privacy: many wanted privacy for the individual, and transparency for thegovernment and corporate elites. The cypherpunks envisioned that one could
hack power relations by writing the right code. Cypherpunk-styled creations—
think of Bitcoin, PGP, Tor, and WikiLeaks—were to be transformative because
they challenge authority and address basic freedoms: freedom of speech,
movement, and economic engagement.69
Exactly how such tools are to shape society is not always obvious. Consider
WikiLeaks. The hope is not just that a better informed public will demandaccountability and change. Rather, Assange sees governmental and corporate
abuse as forms of conspiracy that could be throttled by the mere threat of leaks.
Conspiracies are like graphs, the conspirators nodes, the pairwise relations among
them, the edges. Instead of removing nodes or disrupting links, you can weaken
any conspiracy by suffusing it in an ever-present threat of leaks. The more unjust
the conspiracy, the more likely leaks will occur, and the more damage they will
do. As elites become fearful to conspire, they do so reservedly. The conspiratorial
creature’s blood thickens and it dies.70 It is a fascinating vision.
It is cypherpunks, not cryptographers, who are normally the strongest
advocates for cryptography. Julian Assange writes:67

Andy Greenberg: This Machine Kills Secrets: How WikiLeakers, Cypherpunks,and Hacktivists Aim to Free the World’s Information. Dutton, 2012. Steven Levy:
Crypto: How the Code Rebels Beat the Government Saving Privacy in the Digital
Age. Viking Adult, 2001. Julian Assange, Jacob Appelbaum, Andy Müller-Maguhn,Jérémie Zimmermann: Cypherpunks: Freedom and the Future of the Internet. OR
Books, 2012. Robert Manne: The cypherpunk revolutionary: on Julian Assange. The
Monthly: Australian Politics, Society, & Culture. March 2011.
68
It is the same belief embedded in the work already discussed by David Chaum.
69
I have heard academic cryptographers saying that we deserve credit for these
artifacts, for, regardless of who wrote the code, the ideas stem from cryptographic
notions that come from us. While there is some truth to this, the claim still feels
ungenuine. The work, in each case, arose from somewhere else, employed only old
and basic tools, and was at most modestly embraced by our community.
70
Julian Assange: Conspiracy as governance. Manuscript, December 3, 2006.
http://cryptome.org/0002/ja-conspiracies.pdf. Finn Brunton: Keyspace: reflections
on WikiLeaks and the Assange papers. Radical Philosophy 166, pp. 8–20, Mar/Apr
2011.

18

P. Rogaway
But we discovered something. Our one hope against total domination. A hopethat with courage, insight and solidarity we could use to resist. A strange
property of the physical universe that we live in.
The universe believes in encryption.
It is easier to encrypt information than it is to decrypt it.
We saw we could use this strange property to create the laws of a newworld.71

Similarly, Edward Snowden writes:72
In words from history, let us speak no more of faith in man, but bind him
down from mischief by the chains of cryptography.73

When I first encountered such discourse, I smugly thought the authors were
way over-promising: they needed to tone down this rhetoric to be accurate. I
no longer think this way. More engaged in implementing systems than I’ll everbe, top cypherpunks understand more than I about insecure operating systems,
malware, programming bugs, subversion, side channels, poor usability, small
anonymity sets, and so on. Cypherpunks believe that despite such obstacles,
cryptography can still be transformative.
Cryptography favors whom? Cypherpunk discourse seems sometimes toassume that cryptography will benefit ordinary people. But one has to be careful
here. Cryptography can be developed in directions that tend to benefit the weakor the powerful. It can also be pursued in ways likely to benefit nobody but thecryptographer. Let’s look at some examples.
Encryption. One reason people might assume cryptography to benefit the weakis that they’re thinking of cryptography as conventional encryption. Individuals
with minimal resources can encrypt plaintexts in a manner that even a state-level
adversary, lacking the key, won’t be able to decrypt.
But does it necessarily come out that way? To work, cryptographic primitives
must be embedded into systems, and those systems can realize arrangements ofpower that don’t trivially flow from the nature of the tool. In his typically pithy
way, Schneier reminds people that “encryption is just a bunch of math, and mathhas no agency.”74 If a content-provider streams an encrypted film to a customer
who holds the decryption key locked within a hardware or software boundary
she has no realistic ability to penetrate,75 we’ve empowered content providers,71

Julian Assange: Cypherpunks, op. cit.
I do not know if Snowden considers himself a cypherpunk, but the sentiment
expressed in this quote nicely reflects cypherpunk discourse.
73
Edward Snowden, quoted in Glenn Greenwald, No Place to Hide: Edward Snowden,
the NSA, and the U.S. Surveillance State, 2014. Snowden is reformulating a quote ofThomas Jefferson: “In questions of power then, let no more be heard of confidence
in man but bind him down from mischief by the chains of the Constitution.”
74
Bruce Schneier: Data and Goliath: The Hidden Battles to Collect Your Data andControl Your World. W.W. Norton & Company, 2015. The quote is from p. 131.
75
This was the dream behind the the Trusted Platform Module (TPM), a coprocessor
that implements a standard set of cryptographic operations within a tamper-resistant72

The Moral Character of Cryptographic Work19

not users. If we couple public-key cryptography with a key-escrow system that
the FBI and NSA can exploit, we empower governments, not people.76
All that said, I do believe it accurate to say that conventional encryption does
embed a tendency to empower ordinary people. Encryption directly supports
freedom of speech. It doesn’t require expensive or difficult-to-obtain resources.
It’s enabled by a thing that’s easily shared. An individual can refrain fromusing backdoored systems.77 Even the customary language for talking about
encryption suggests a worldview in which ordinary people—the world’s Alices
and Bobs—are to be afforded the opportunity of private discourse. And coming
at it from the other direction, one has to work to embed encryption within anarchitecture that props up power, and one may encounter major obstacles tosuccess. The Clipper Chip completely failed. Trusted Computing mostly did.78
IBE.79 What about identity-based encryption, IBE? The setting was proposedby Shamir, with Boneh and Franklin, years later, providing a satisfying, provably
secure realization.80 The aim is to allow a party’s email address, for example, toserve as his public key. So if Alice already knows the email address for Bob, she
won’t need to obtain his public key to send him an encrypted message: she justencrypts under Bob’s email address.
But this convenience is enabled by a radical change in the trust model: Bob’s
secret key is no longer self-selected. It is issued by a trusted authority. Thatauthority knows everyone’s secret key in the system. IBE embeds key escrow—indeed a form of key escrow where a single entity implicitly holds all secretkeys—even ones that haven’t yet been issued. And even if you do trust the keygenerating authority, a state-level adversary now has an extremely attractive
locus to subpoena or subvert. In the end, from a personal-privacy point of view,IBE might seem like an enormous leap backwards.
boundary. See Wikipedia entry: Trusted Platform Module, and Ross Anderson’s
FAQ: ‘Trusted Computing’ Frequently Asked Questions. http://www.cl.cam.ac.uk/∼rja14/tcpa-faq.html
76
For a nice discussion of the Clipper Chip, see Michael Froomkin: The metaphor is the
key: cryptography, the clipper chip, and the constitution. University of Pennsylvania
Law Review, 143(3), pp. 709–897, 1995.
77
This may be theoretically possible but practically difficult: it might be hard toaccomplish for technically unsophisticated people. This is why it is said: When
crypto is outlawed only outlaws will have crypto (or privacy, or security) (original
attribution unknown).
78
On the other hand, some other forms of cryptographically enabled DRM (Digital
Rights Management), including the CSS (Content Scrambling System) used to makemore difficult the copying of DVDs, has been reasonably effective (from the point ofview of content owners).
79
Ideas expressed on this topic are joint with Mihir Bellare.
80
Adi Shamir: Identity-based cryptosystems and signature schemes. Crypto ’84, pp. 4753, 1984. Dan Boneh and Matthew Franklin: Identity-based encryption from the
Weil pairing. SIAM J. of Computing, 32(3), pp. 586–615, 2003. See also Ryuichi
Sakai, Kiyoshi Ohgishi, Masao Kasahara: Cryptosystems based on pairing. The 2000
Symposium on Cryptography and Information Security, 2000.

20

P. Rogaway

Descriptions of IBE don’t usually emphasize the change in trust model.81
And the key-issuing authority seems never to be named anything like that: it’s
just the PKG, for Private Key Generator. This sounds more innocuous than
it is, and more like an algorithm than an entity. In papers, the PKG further
recedes from view because it is the tuple of algorithms, not the entities that one
imagines to run them, that grounds formal definitions and proofs.
To be clear, I am not condemning IBE as some sort of fascist technology. Thatsounds silly. Nor am I suggesting that IBE can’t be refined in ways to makethe trust model less authoritarian.82 Yet one can easily see the authoritarian
tendency built into IBE. And technologies, while adaptable, are not infinitely
so. As they evolve, they tend to retain their implicit orientations.
Differential privacy. Let’s consider differential privacy.83 Dwork says that-differential privacy “addresses concerns that any participant might have about
the leakage of her personal information: even if the participant removed herdata from the data set, no outputs . . . would become significantly more or lesslikely.”84
At some level, this sounds great: don’t we want to protect individuals fromprivacy-compromising disclosures from corporate or governmental datasets? Buta more critical and less institutionally friendly perspective makes this definitionalline seem off.85 Most basically, the model implicitly paints the database owner(the curator) as the good guy, and the users querying it, the adversary. If power
would just agree to fudge with the answers in the right way, it would be fine forit to hold massive amounts of personal data about each of us. But the historyof data-privacy breaches suggests that the principal threat to us is from thedatabase owner itself, and those that gain wholesale access to the data (forexample, by theft or secret government programs). Second, the harm differentialprivacy seeks to avoid is conceived of in entirely individualistic terms. But privacy
violations harm entire communities. The individualistic focus presupposes anarrow conception of privacy’s value. Finally,86 differential privacy implicitly
presupposes that the data collection serves some public good. But, routinely,
this is a highly contestable claim. The alternative of less data collection, or no81

For example, the Wikipedia entry “ID-based encryption” (Nov. 2015) has a lead
section that fails to even mention the presence of a key-issuing authority.
82
For many IBE schemes it is easy to distribute the PKG’s secret, the master key,
across a set of parties. One could further arrange for distributed generation of thiskey, so no one party ever held it. Both of these points are made in the original Bonehand Franklin paper: op. cit., Section 6, Distributed PKG.
83
See, for example: Cynthia Dwork: Differential privacy: a survey of results. Theory
and Applications of Models of Computation, pp. 1–19, Springer, 2008.
84
Ibid, p. 2.
85
For a quite different critique of differential privacy, see Jane Bambauer,
Krishnamurty Muralidhar, Rathindra Sarathy: Fool’s gold: an illustrated critiqueof differential privacy. Vanderbilt Journal of Entertainment and Technology Law,
16(4), pp. 701–755, Summer 2014.
86
Colleen Swanson, personal communications.

The Moral Character of Cryptographic Work21

data collection at all, is rarely even mentioned. In the end, one must compare
the reduction in harm actually afforded by using differential privacy with theincrease in harm afforded by corporations having another means of whitewash,and policy-makers believing, quite wrongly, that there is some sort of cryptomagic to protect people from data misuse.
I recently asked an expert in differential privacy, Ilya Mironov, for his reaction
to my harsh critique. He explained that the abstract roles in differential-privacy
settings need not correspond to business relationships in the obvious way. For
example, a privacy-conscious organization might choose to make its own analysts
access sensitive data through an API that provides some differential-privacy
guarantee, effectively treating its own employees as “adversaries.” Mironov
also explained that there are variant notions of differential privacy that do
not implicitly regard the database owner as good, and those querying it as
bad. He described differential privacy in the local model,87 where everyone
keeps his data to himself. They can distributively compute the responses toqueries. Fundamentally, Mironov explained, the definition of differential privacy
is agnostic to the data model.
While everything explained makes good sense, I don’t think it changes thelandscape. No actual mechanism can be agnostic to what data resides where.
And at the point when a data-mining architecture and mechanism is laid
down, considerations of efficiency, familiarity, and economics—not to mention
authorities’ fundamental desire to have and to hold the data—make it easy to
predict what will happen: almost always, a centralized design will emerge. To
me, differential privacy may be as authoritarian in its conceptual underpinnings
as IBE.
FHE and iO. Ever since Craig Gentry’s groundbreaking work,88 fully homomorphic encryption (FHE) has been a target of enormous intellectual capital.
In brief, FHE allows you to outsource your data, encrypted under a public key
of your choosing, to a service provider. Later, you can ask that party whatever
you’d like about your plaintext. The service provider computes the encrypted
answer, not knowing what it means. This is returned to you for decryption.
From a political perspective, FHE sounds empowering—even utopian. The
powerful party, say a cloud service provider, is denied access to your data. You
sidestep the Faustian bargain that routinely underlies cloud computing.89
87

Cynthia Dwork, Krishnaram Kenthapadi, Frank McSherry, Ilya Mironov, and Moni
Naor: Our data, ourselves: privacy via distributed noise generation. Eurocrypt 2006,
pp. 486–503. For an exploration of limitations of local model, also see: Shiva Prasad
Kasiviswanathan, Homin K. Lee, Kobbi Nissim, Sofya Raskhodnikova, and Adam
Smith: What can we learn privately? SIAM Journal of Computing, 40(3), pp. 793–
826, 2011. Amos Beimel, Kobbi Nissim, and Eran Omri: Distributed private data
analysis: on simultaneously solving how and what. CRYPTO 2008, pp. 451-468. Also
arXiv:1103.2626
88
Craig Gentry: Fully homomorphic encryption using ideal lattices. STOC 2009.
89
I refer, of course, to the exchange of personal information for a network service.

22

P. Rogaway

But the analysis above is specious. It is quite speculative if FHE will ever
evolve into something practically useful. If you want to assess the politicalleanings of something of speculative utility, you shouldn’t just assume that it
will give rise to the touted applications, and then try to see who would win and
who would lose. It’s too conjectural. It is better to focus on how the pursuitchanges us in the here and now.
And on that, I would say that FHE, along with iO,90 have engendered a newwave of exuberance. In grant proposals, media interviews, and talks, leading
theorists speak of FHE and iO as game-changing indications of where we havecome.91 Nobody seems to emphasize just how speculative it is that any of thiswill ever have any impact on practice. Nor do people emphasize our vanishing
privacy, our lousy computer security, or how little modern cryptography hasreally done to change this landscape. And this has consequences. (a) It misleads
the public about where we stand. (b) It shifts financial resources away from areas
more likely to have social utility. (c) It encourages bright young researchers towork on highly impractical directions. (d) And it provides useful cover to thestrongest opponents of privacy: defense and intelligence agencies.
Let me expand on the last claim. Here is what DARPA Program Director
Dan Kaufman had to say about FHE in a 2014 interview:
Imagine a future that says: OK, I have to collect everything for big data towork because if I knew what wasn’t relevant it wouldn’t be big data. But I
don’t want the government to just willy-nilly look through my emails: thatfeels creepy. . . .
So this guy, Craig Gentry, . . . showed that you could . . . take a piece of
data, encrypt it, send it down the wire, never decrypt it, [but] still perform[computation] . . . on it. It sounds crazy, except he showed you can do it . . ..
You could imagine the following: . . . [Organizations] collect . . . data but
only in . . . encrypted form . . .. Now let’s say you believe there is a bad guy
hiding somewhere in this encrypted data. So, I come up with a bunch of searchterms . . .. I could then go to a court . . . [and they] could say “yeah, that looks
reasonable.” I put the search into the engine but . . . all that comes out is anumber: how many people meet that criteria . . . You go back to the FISA
court, and say O.K. guys, we have 12. . . . I picture FISA putting in a key, and90

The acronym is for indistinguishability obfuscation. Sanjam Garg, Craig Gentry,
Shai Halevi, Mariana Raykova, Amit Sahai, and Brent Waters: Candidate
indistinguishability obfuscation and functional encryption for all circuits. FOCS
2013, pp. 40–49. Earlier work introducing iO: Boaz Barak, Oded Goldreich, Russell
Impagliazzo, Steven Rudich, Amit Sahai, Salil Vadhan, and Ke Yang. On the(im)possibility of obfuscating programs. JACM, 59(2):6, 2012. Earlier version in
CRYPTO 2001.
91
See, for example: Erica Klarreich: Perfecting the art of sensible nonsense. QuantaMagazine, Jan. 30, 2014. “Researchers are hailing the new work as a watershed
moment for cryptography. . . . If the problem of obfuscation has been solved, what
remains for cryptographers?” Kevin Hartnett: A New Design for Cryptography’sBlack Box. Quanta Magazine, Sep. 2, 2015. “New advances show how near-perfectcomputer security might be surprisingly close at hand.”The Moral Character of Cryptographic Work23

then the Agency putting in a key, and they both turn it. And [at] that point,
for the first time, . . . are those 12 now revealed.92

Of course, it’s utter nonsense. To begin with, there’s no way to make sense of who
holds what key and what data for FHE to even apply. We’re also told: that weneed to collect everything because, if we didn’t, we wouldn’t have enough datato have lots of data; that the government will be careful, as it would be “creepy”
if they weren’t; that they’ll get court orders—even, apparently, to discover thenumber of people in datasets who satisfy some specified search criteria; and thatto get personally identifiable information, they’ll need to have the cooperationof the NSA and the FISA court.
Kaufman’s inchoate interview is but a tiny patch of discourse from an oceanof misdirection on privacy. It doesn’t impugn FHE, but it does suggest how poweraims to use such work: to let them mumble words that sound privacy-friendly.
Providing strong funding for FHE and iO provides risk-free political cover. It
supports a storyline that cloud storage and computing is safe. It helps entrenchfavored values within the cryptographic community: speculative, theory-centric
directions. And it helps keep harmless academics who could, if they got feisty,
start to innovate in more sensitive directions.
Cryptanalysis. Finally, let me briefly mention cryptanalysis. One might
misinterpret the academic cryptanalytic undertaking as an attack on the privacyof legitimate users—an attack on the inoffensive Alice and Bob—which would
thus seem to favor power.93 But this is the opposite of the right view. The reason
that academic cryptographers do cryptanalysis is to better inform the designers
and users of cryptosystems about what is and what is not safe to do. The activity
is not done to surveil people, but to help ensure that people are not surveilled—
at least by cryptanalytic means. And the work routinely has exactly that effect.
The history of WEP provides a nice example.94
When the NSA or GCHQ engage in cryptanalysis, it is for a very different
purpose, and it has a very different effect. Does that mean that cryptanalysis
done by one group of people (spooks) will tend to favor authority, while
cryptanalysis done by another group of people (academics) will tend in the exact
opposite direction? It does. The specific work will be different; its dissemination
will be different; and its impact on human rights will be different.
Unthreateningly engaged. Of course it hasn’t escaped the notice of intelligence agencies that the majority of the academic cryptographic community is
92

Evelyn M. Rusli: A Darpa [sic] director on fully homomorphic encryption (or one
way the U.S. could collect data). Wall Street Journal blog: blogs.wsj.com. March 9,
2014. Quote edited for punctuation.
93
Adi Shamir, personal communications, December 2015.
94
WEP (Wired Equivalent Privacy) was a badly flawed cryptographic protocol
underlying early 802.11 (Wi-Fi) networks. A series of devastating attacks resulted in
WEP’s replacement by a better scheme. The first of the attacks was: Scott Fluhrer,
Itski Mantin, and Adi Shamir: Weaknesses in the key scheduling algorithm of RC4.
Selected Areas of Cryptography (SAC 2001), pp. 1–24, 2001.

24

P. Rogaway

unthreateningly engaged. In a declassified trip-report about Eurocrypt 1992, the
NSA author opines, for example:95
There were no proposals of cryptosystems, no novel cryptanalysis of old
designs, even very little on hardware design. I really don’t see how things
could have been better for our purposes.

The NSA’s newsletter in which this report appears would never again mention
that academic cryptographic community.96 Nor did any released Snowdenderived document discuss anything of our community.97 It’s as though we progressed from a band of philosophers98 worth a few pages of snarky commentary99
to an assemblage too insignificant even for that.
Conclusion to part 2. A 2013 essay by Arvind Narayanan suggests a simple
taxonomy for cryptographic work:100 there’s crypto-for-security and crypto-forprivacy. Crypto-for-security is crypto for commercial purposes. It’s the crypto in
TLS, payment cards, and cell phones. Crypto-for-privacy has social or politicalaims. Here the author distinguishes between pragmatic crypto—which is about
trying to use cryptography to retain our predigital privacy—and cypherpunk
crypto—the grander hope of using cryptography to precipitate sweeping social
or political reforms. The author suggests that crypto-for-security has done well,
but crypto-for-privacy has fared badly.
I think Narayanan’s division is illuminating, but he fails to mention that mostacademic cryptography isn’t really crypto-for-security or crypto-for-privacy: it
is, one could say, crypto-for-crypto—meaning that it doesn’t ostensibly benefit
commerce or privacy, and it’s quite speculative if it will ever evolve to do either.
Perhaps every field eventually becomes primarily self-referential. Maybe this iseven necessary, to some extent. But for cryptography, much is lost when we
become so inward-looking that almost nobody is working on problems we could
help with that address some basic human need. Crypto-for-crypto starves cryptofor-privacy, leaving a hole, both technical and ethical, in what we collectively do.
95

Eurocrypt 1992 reviewed. Author name redacted. National Security Agency,
CRYPTOLOG. First issue of 1994. Available at http://tinyurl.com/eurocrypt199296
136 editions of the NSA newsletter, CRYPTOLOG, are available, in redacted form.
The period covered is 1974–1997. An archive can be found at https://www.nsa.gov/
public info/declass/cryptologs.shtml
97
Of course Tor is extensively discussed in Snowden documents—but it would be wrong
to view Tor as a contribution springing from the cryptographic community, nor as
something much addressed within it.
98This is the term NSA author above prefers.
99
The use of the word “snarky” here is from Bruce Schneier: Snarky 1992 NSA reporton academic cryptography. Blog post, Nov. 18, 2014. https://www.schneier.com/
blog/archives/2014/11/snarky 1992 nsa.html
100
Arvind Narayanan: What happened to the crypto dream? Part 1 in IEEE Security
and Privacy Magazine, 11(2), pp. 75–76, 2013. Part 2 in IEEE Security and Privacy
Magazine, 11(3), pp. 68–71, 2013.

The Moral Character of Cryptographic Work

25

Part 3: The dystopian world of pervasive surveillance
Mass surveillance has motivated the contents of this essay, but is it so serious
a thing? Before the Snowden revelations,101 I myself didn’t really think so.
Environmental problems seemed more threatening to man’s future, and mycountry’s endless wars seemed more deserving of moral consternation. It wasn’t
until Snowden that I finally internalized that the surveillance issue was grave, wasclosely tied to our values and our profession, and was being quite misleadingly
framed.
Law-enforcement framing. The framing of mass surveillance determines what
one thinks it is about.102 And mass surveillance has been brilliantly framed byauthority so as to slant discourse in a particular and predictable direction. Let me
describe what I’ll call the law-enforcement framing, as regularly communicatedby (U.S.) FBI Director James Comey:103
1. Privacy is personal good. It’s about your desire to control personal information about you.
2. Security, on the other hand, is a collective good. It’s about living in a safe
and secure world.
3. Privacy and security are inherently in conflict. As you strengthen one, you
weaken the other. We need to find the right balance.
4. Modern communications technology has destroyed the former balance. It’s
been a boon to privacy, and a blow to security. Encryption is especiallythreatening. Our laws just haven’t kept up.104
5. Because of this, bad guys may win. The bad guys are terrorists, murderers,
child pornographers, drug traffickers, and money launderers.105 The technology that we good guys use—the bad guys use it too, to escape detection.
101

For a review of key information learned from the Snowden revelations, see the
EFF webpages “NSA Spying on America,” https://www.eff.org/nsa-spying, and
the ACLU webpage, “NSA Surveillance,” https://www.aclu.org/issues/nationalsecurity/privacy-and-surveillance/nsa-surveillance
102
Collin Bennett: The Privacy Advocates: Resisting the Spread of Surveillance. The
MIT Press, 2008.
103
James Comey: “Going Dark: Are Technology, Privacy, and Public Safety ona Collision Course?” Speech at the Brookings Institute, October 16, 2014.
http://tinyurl.com/comey-going-dark
104
Comey speaks particularly of CALEA, the Communications Assistance for Law
Enforcement Act, the 1994 U.S. law mandating lawful intercept capabilities bebuilt into telecommunications equipment—but does not mandate such abilities forencrypted email, instant messaging, and the like.
105
The traditional cast of evil-doers, the “four horsemen of the info-pocalypse,” omits
murderers from this list of five; see Assange et al., Cypherpunks, op. cit.. Note thatin Comey’s Brookings Institute speech, the speaker adds murderers to this list, andsubtracts money launderers. The move is shrewed; money laundering is technocratic
and legalistic crime compared to murder.

26

P. Rogaway

6. At this point, we run the risk of Going Dark.106 Warrants will be issued,
but, due to encryption, they’ll be meaningless. We’re becoming a country ofunopenable closets. Default encryption may make a good marketing pitch,but it’s reckless design. It will lead us to a very dark place.
The narrative is inconsistent with the history of intelligence gathering, and with
the NSA’s own mission statement.107 Yet the narrative’s uneasy coexistencewith reality hasn’t mattered. It is, in fact, beautifully crafted to frame mattersin a way guaranteed to lead discourse where authority wants it to go. It is abrilliant discourse of fear: fear of crime; fear of losing our parents’ protection;even fear of the dark. The narrative’s well-honed deceptiveness is itself a formof tradecraft.108
Surveillance-studies framing. Of course there are radically different ways
to frame mass surveillance. Consider the following way to do so, which follows
often-heard thoughts from cypherpunks and surveillance studies.109
1. Surveillance is an instrument of power.110 It is part of an apparatus ofcontrol. Power need not be in-your-face to be effective: subtle, psychological,
nearly invisible methods can actually be more effective.
2. While surveillance is nothing new, technological changes have given governments and corporations an unprecedented capacity to monitor everyone’s
communication and movement. Surveilling everyone has became cheaper
than figuring out whom to surveil, and the marginal cost is now tiny.111 The
Internet, once seen by many as a tool for emancipation, is being transformed
into the most dangerous facilitator for totalitarianism ever seen.112
3. Governmental surveillance is strongly linked to cyberwar. Security vulnerabilities that enable one enable the other. And, at least in the USA, the106

The phrase (including the capitalization) is from the Comey speech just cited.
Church Committee Reports, 1975–1976. Available at http://www.aarclibrary.org/
publib/church/reports/contents.htm. Frank Donner: The Age of Surveillance: The
Aims and Methods of America’s Political Intelligence System. Vintage Press, 1981.
Classified NSA document: SIGINT Mission Strategic Plan FY2008–2013. Oct. 3,
2007. http://tinyurl.com/sigint-plan
108“Verbal deception is itself an intelligence practice,” explains Donner, op. cit., p. xiv.
See too his Appendix I, pp. 464–466.
109
Michel Foucault: Discipline and Punish: The Birth of the Prison. Alan Sheriden,translator. 1975/1977. Frank Donner, op. cit. Assange et al., op. cit. David Lyon:
Surveillance Studies: An Overview. 2007. David Murakami Wood and Kirstie Ball:
A Report on the Surveillance Society. Sep. 2006.
110
Even the etymology of surveillance suggests this: from the French: sur, meaning
over, plus veiller, meaning to watch. Thus: to watch from above, from a positionof power. An interesting turn on this conception is the notion of sousveillance, as
coined by Steve Mann. See Wikipedia entry: Sousveillance.
111
Adding one more phone number to a wiretap is almost free. Kevin S. Bankston andAshkan Soltani: Tiny constables and the cost of surveillance: making cents out of
United States v. Jones. The Yale Law Journal, vol. 123, Jan. 2014.
112
This sentence is a slightly modified from Assange et al., Cypherpunks, op. cit..
107

The Moral Character of Cryptographic Work27

same individuals and agencies handle both jobs. Surveillance is also strongly
linked to conventional warfare. As Gen. Michael Hayden has explained, “wekill people based on metadata.”113 Surveillance and assassination by drones
are one technological ecosystem.
4. The law-enforcement narrative is wrong to position privacy as an individual
good when it is, just as much, a social good. It is equally wrong to regard
privacy and security as conflicting values, as privacy enhances security as
often as it rubs against it.
5. Mass surveillance will tend to produce uniform, compliant, and shallow
people.114 It will thwart or reverse social progress. In a world of ubiquitous
monitoring, there is no space for personal exploration, and no space tochallenge social norms, either. Living in fear, there is no genuine freedom.
6. But creeping surveillance is hard to stop, because of interlocking corporate
and governmental interests.115 Cryptography offers at least some hope. Withit, one might carve out a space free of power’s reach.
History teaches that extensive governmental surveillance becomes politicalin character. As civil-rights attorney Frank Donner and the Church Commission
reports thoroughly document, domestic surveillance under U.S. FBI director
J. Edgar Hoover served as a mechanism to protect the status quo andneutralize change movements.116 Very little of the FBI’s surveillance-related
efforts were directed at law-enforcement: as the activities surveilled were rarely
illegal, unwelcome behavior would result in sabotage, threats, blackmail, andinappropriate prosecutions, instead. For example, leveraging audio surveillancetapes, the FBI’s attempted to get Dr. Martin Luther King, Jr., to kill himself.117
U.S. universities were thoroughly infiltrated with informants: selected students,
faculty, staff, and administrators would report to an extensive network of
FBI handlers on anything political going on on campus. The surveillanceof dissent became an institutional pillar for maintaining political order. The
U.S. COINTELPRO program would run for more than 15 years, permanently
reshaping the U.S. political landscape.118
113

Michael Hayden: The Johns Hopkins Foreign Affairs Symposium Presents: The
Price of Privacy: Re-Evaluating the NSA. May 9, 2014. Video, available athttps://www.youtube.com/watch?v=kV2HDM86XgI
114
For the last of these claims: “A life spent entirely in public, in the presence of others,
becomes, as we would say shallow.” Hannah Arendt, The Human Condition. Chicago
University Press, 1959.
115
Of course corporations and governments also, on occasion, have competing interests,
as when publicity on surveillance scares away customers. This is the force motivating
the principles enunciated in https://www.reformgovernmentsurveillance.com/
116
Church, op. cit.; Donner, op. cit.; and Julian Sanchez: Wiretapping’s true danger. Los
Angeles Times, March 16, 2008. http://articles.latimes.com/2008/mar/16/opinion/
op-sanchez16
117
Nadia Kayyali: FBI’s “Suicide Letter” to Dr. Martin Luther King, Jr.,and the Dangers of Unchecked Surveillance. Nov. 12, 2014. EFF website,
http://tinyurl.com/fbi-suicide-letter
118
Church Committee Reports, op. cit., and Frank Donner, op. cit.

28

P. Rogaway

Our dystopian future. Where mass surveillance leads has been brilliantly
explored in fictional accounts, starting with Yevgeny Zamyatin’s 1921 novel We(which inspired Orwell’s 1984). Set in a future of total surveillance, the denizensof the “One State” have internalized lessons such as: “we” is from God, and “I”
is from the devil; that imagination is illness; and that the key to ridding man ofcrime is ridding him of freedom.
But you don’t have to reach to fictional or historical accounts to anticipate
where we are headed. In a 2012 newsletter column, NSA’s “SIGINT Philosopher,” Jacob Weber, shares his own vision. After failing an NSA lie-detector
test, he says:
I found myself wishing that my life would be constantly and completely
monitored. It might seem odd that a self-professed libertarian would wish
an Orwellian dystopia on himself, but here was my rationale: If people knew a
few things about me, I might seem suspicious. But if people knew everything
about me, they’d see they had nothing to fear.
. . . A target that119 has no ill will to the U.S., but which is being monitored,needs better and more monitoring, not less. So if we’re in for a penny, we need
to be in for a pound.120

Shrouded in enormous secrecy and complexity, the basic contours of thesurveillance state are fundamentally unknowable. What is the individual to
do? With everyone’s communication machine monitored, he knows that he’s ade facto target. Millions of observations are made of his life. He is analyzed
by techniques he cannot remotely understand. He knows that today’s data,
and yesterday’s, will be scrutinized by tomorrow’s algorithms. These will
employ sophisticated natural-language processing, but probably won’t actually
understand human discourse. With all this, the rational individual has no choice
but to watch what he says, and to try to act like everyone else.
The film Citizenfour (2014) is at its best when it manages to sketch the shapeof this emerging world. One reviewer writes of the film
evoking the modern state as an unseen, ubiquitous presence, an abstraction
with enormous coercive resources at its disposal. . . .
It is everywhere and nowhere, the leviathan whose belly is our native
atmosphere. Mr. Snowden, unplugging the telephone in his room, hiding under
119

Observe the use of that and which, rather than who: the target is not a person but
a thing.
120
Jacob Weber (deanonymized by The Intercept readers): The SIGINT Philosopher Is
Back — with a New Face! SIDtoday. May 29, 2012. goo.gl/TyBzig
Peter Maass writes of the SIGINT Philosopher in: The Philosopher of Surveillance,
The Intercept, Aug. 11, 2015. His article may be my favorite from the entire corpus
of articles coming out of the Snowden revelations. It functions at multiple levels,
giving the reader the uncomfortable sense of doing to another (and even enjoying
to do to another) precisely what he would not want done to himself. “Modern life
is such an unholy mix of voyeurism and exhibitionism,” says the character of Stella
Gibson (Gillian Anderson) in Allan Cubitt’s TV series The Fall (2014) (season 2,
episode 4).

The Moral Character of Cryptographic Work29

a blanket when typing on his laptop, looking mildly panicked when a fire alarmis tested on his floor, can seem paranoid. He can also seem to be practicing akind of avant-garde common sense. It’s hard to tell the difference, and [this]. . . can induce a kind of epistemological vertigo. What do we know about what
is known about us? Who knows it? Can we trust them?121

To be more prosaic: I pick up the phone and call my colleague, Mihir Bellare,
or I tap out an email to him. How many copies of this communication will be
stored, and by whom? What algorithms will analyze it—now and in the future?
What other data will it be combined with in an attempt to form a picture of me?
What would trigger a human analyst to get involved? Might my call or email
contribute to a tax audit, a negative grant-funding decision, some Hoover-style
dirty tricks, or even an assassination? There is not a single person who knows
the answer to these questions, and those who know most aren’t about to tell.
Conclusion to part 3. Ultimately, I’m not much interested in individual
grievances over privacy; I am far more concerned with what surveillance does tosociety and human rights. Totalized surveillance vastly diminishes the possibilityof effective political dissent. And without dissent, social progress is unlikely.
Consider an event like the 1971 burglary of the FBI branch office inMedia, Pennsylvania.122 With the degree of surveillance we now live under,
the whistleblowers—beginning with that feisty physics professor who led theeffort123 —would be promptly arrested, and even charged with espionage. They
would have spent years in prison, or even faced execution. Facing such outcomes
and odds, the activists would not have attempted their daring burglary. In an
essay that focuses on remedies for excessive surveillance, Richard Stallman asks
Where exactly is the maximum tolerable level of surveillance, beyond which
it becomes oppressive? That happens when surveillance interferes with thefunctioning of democracy: when whistleblowers (such as Snowden) are likely
to be caught.124

Online and telephone surveillance already results in the imprisonment ofpolitical dissidents around the world,125 and it undergirds my own country’s
drone-assassination program.126 In the U.S., Miami-model policing127 has made121

A. O. Scott: Intent on defying an all-seeing eye: ‘Citizenfour,’ a documentary about
Edward Snowden. New York Times movie review, Oct. 23, 2014.
122
Betty Medsger: The Burglary: The Discovery of J. Edgar Hoover’s Secret FBI. Knopf,
2014.
123
William Davidon, as revealed in Medsger, The Burglary, Ibid.
124
Richard Stallman: How much surveillance can democracy withstand? Wired, Oct. 14,
2013. See also http://www.gnu.org/philosophy/surveillance-vs-democracy.html
125
Reporters without Borders: The Enemies of Internet: Special Edition: Surveillance.
2013. http://surveillance.rsf.org/en/
126
Jeremy Scahill and Glenn Greenwald: The NSA’s secret role in the U.S. assassination
program. The Intercept, Feb 9, 2014.
127
Greg Elmer and Andy Opel: Preempting Dissent: The Politics of an Inevitable
Future. Arbeiter Ring Publishing, 2008. Also see the film, Preempting Dissent (2014),
by the same team. http://preemptingdissent.com/

30

P. Rogaway

attending political protests (or just being near one in your car, or with yourphone) an intimidating proposition. With journalists’ communications routinely
monitored, investigative journalism is under attack.128 Is democracy or social
progress possible in such an environment?
But, despite all these arguments, I am skeptical about rationalist accountsof ethical affronts, be it mass surveillance or anything else. If we behave morally,
it is not because of rational analyses, but an instinctual preference for liberty,
empathy, or companionship.129 As Schneier points out, animals don’t like to be
surveilled because it makes them feel like prey, while it makes the surveillor feel
like—and act like—a predator.130 I think people know at an instinctual levelthat a life in which our thoughts, discourse, and interactions are subjected toconstant algorithmic or human monitoring is no life at all. We are sprinting
towards a world that we know, even without rational thought, is not a place
where man belongs.

Part 4: Creating a more just and useful field
What can we cryptographers realistically do to collectively up our contribution
to crypto-for-privacy? I claim no easy answers. I can offer only modest ideas.
Secure messaging in the untrusted-server model. Problem selection is
the most obvious aspect in determining our community’s impact, and secure
messaging, in all its forms, remains the most outstanding problem in cryptofor-privacy. While mix nets, onion routing, and DC nets have all proven to behighly useful,131 it is not too late to be thinking on new architectures for securecommunications.
Consider the following problem, which is inspired by Pond and the PANDA
protocol that it can use.132 The aim is similar to Adam Langley’s Pond protocol:
to create an alternative to email or instant messaging but where “big brother”
is unable to figure out who is communicating with whom. Unlike Pond, I don’t
want to rely on Tor, for we seek security in the face of a global, active adversary(as well as a clean, provable-security treatment). Tor can always be layered on
top, as a heuristic measure, to hide system participants.
128

Human Rights Watch: With liberty to monitor all: how large-scale US surveillanceis harming journalism, law, and American democracy. July 2014.
129
Michael Gazzaniga: The Ethical Brain: The Science of Our Moral Dilemmas. Dana
Press, 2005.
130
Bruce Schneier, op. cit., paraphrasing a sentence of p. 127.
131
Joan Feigenbaum and Bryan Ford: Seeking anonymity in an Internet Panopticon.
Communications of the ACM, 58(10), October 2015.
132
Adam Langley: Pond. Webpages rooted at https://pond.imperialviolet.org/. For
PANDA, see Jacob Appelbaum and “another cypherpunk”: Going dark: phrase automated nym discovery authentication: or, finding friends and lovers using the PANDA
protocol to re-nymber after everything is lost: or, discovering new Pond users easily.
Manuscript, Feb 21, 2014. https://github.com/agl/pond/tree/master/papers/panda

The Moral Character of Cryptographic Work31

The intent is this. Pairs of people who want to communicate are assumed
to initially share a password. They won’t directly talk with one another; rather,
all communications will go through an untrusted server. First, parties upgrade
their shared password to a strong key with an anonymous rendezvous protocol.
Thereafter, the sender can deposit a (constant-length) encrypted message at theserver. When a party wants to retrieve his ith message, he’ll interact with thesame server, which gives him a string computed from the database contents. The
value permits the receiver to recover the intended message—or, alternatively, an
indication that there is no such ith message for him. But, throughout, all theserver ever sees are parties depositing random-looking strings to the server, andparties collecting random-looking strings from the server, these computed byapplying some non-secret function to the server’s non-secret database. Neither
the server nor an active, global adversary can figure out who has communicatedwith whom, or even whether a communications has taken place. The goal is to
do all this as efficiently as possible—in particular, much more efficiently than
the server just handing each recipient its entire database of encrypted messages.
In ongoing work, colleagues and I are working out a provable-security
treatment for the approach above. It uses conventional, game-based definition,
not the fuzzy concepts or vocabulary from much of the anonymity literature.133
We hope that the anonymous messaging in this untrusted-server model will
eventually prove practical for the high-latency setting. We will see.
Bigkey cryptography Let me next describe some recent work by Mihir Bellare,
Daniel Kane, and me that we call bigkey cryptography.134
The intent of bigkey cryptography is to allow cryptographic operations todepend on enormous keys—megabytes to terabytes long. We want our keys solong that it becomes infeasible for an adversary to exfiltrate them. Yet using
such a bigkey mustn’t make things slow. This implies that, with each use, onlya small fraction of the bigkey’s bits will be inspected.
The basic idea is not new: the concept is usually referred to as security in thebounded-retrieval model.135 But our emphasis is new: practical and general tools,
133

An ambitious but informal attempt to unify terminology and concepts inprivacy and anonymity is provided by Andreas Pfitzmann and Marit Hansen:
Anonymity, unlinkability, undetectability, unobservability, pseudonymity, andidentity management — a consolidated proposal for terminology. Version v0.34.
Aug. 10, 2010. Manuscript at http://dud.inf.tu-dresden.de/Anon Terminology.shtml
134
Mihir Bellare, Daniel Kane, Phillip Rogaway: Bigkey cryptography: symmetricencryption with enormous keys and a general tool for achieving key-exfiltration
resistance. Manuscript, 2015.
135
Stefan Dziembowski: Intrusion-resilience via the bounded-storage model. TCC 2006.
Giovanni Di Crescenzo, Richard J. Lipton, Shabsi Walfish: Perfectly secure password
protocols in the bounded retrieval model. TCC 2006. David Cash, Yan Zong Ding,
Yevgeniy Dodis, Wenke Lee, Richard J. Lipton, Shabsi Walfish: Intrusion-resilient
key exchange in the bounded retrieval model. TCC 2007. Joël Alwen, Yevgeniy
Dodis, Daniel Wichs: Survey: leakage resilience and the bounded retrieval model.
ICITS 2009. Work in the bounded-retrieval model has earlier roots in Maurer’s

32

P. Rogawaywith sharp, concrete bounds. We have no objection to using the random-oracle
model to achieve these ends.
Suppose you have a bigkey K. You want to use it for some protocol P thathas been designed to use a conventional-length key K. So choose a random
value R (maybe 256 bits) and hash it to get some number p of probes into thebigkey:i1 = H(R, 1)

i2 = H(R, 2)...

ip = H(R, p) .

Each probe ij points into K: it’s a number between 1 and |K|. So you grab the pbits at those locations and hash them, along with R, to get a derived key K:
K = H 0 (R, K[i1 ], . . . , K[ip ]) = XKEY(K, R) .
Where you would otherwise have used the protocol P with a shared key K, youwill now use P with a shared bigkey K, a freshly chosen R, this determining theconventional key K = XKEY(K, R).
We show that derived-key K is indistinguishable from a uniformly random
key K 0 even if the adversary gets R and can learn lots of information about thebigkey K. The result is quantitative, measuring how good the derived key is as
a function of the length of the bigkey, the number of bits leaked from it, thenumber of probes p, the length of R, and the number of random-oracle calls.
At the heart of this result is an information-theoretic question we call thesubkey-prediction problem. Imagine a random key K that an adversary canexport ` < |K| bits of information about. After that leakage, we select p random
locations into K, give those locations to the adversary, and ask the adversary
to predict those p bits. How well can it do?
It turns out that the adversary can do better than just recording ` bits of the
key K and hoping that lots of probes fall there. But it can’t do much better. Had
nothing been leaked to the adversary, ` = 0, then each probe would contributeabout one bit of entropy to the random variable the adversary must guess. But if,
say, half the key is leaked, ` ≤ |K|/2, each probe will now contribute about 0.156
bits of entropy.136 The adversary’s chance of winning the subkey-prediction game
will be bounded by something that’s around 2−0.156p . One needs about p = 820
probes for 128-bit security, or twice that for 256-bit security.
I think that the subkey prediction problem, and the key-encapsulation
algorithm based on it, will give rise to nice means for exfiltration-resistantauthenticated-encryption and pseudorandom generators.137 In general, I see
bounded-storage model: Ueli Maurer: Conditionally-perfect secrecy and a provablysecure randomized cipher. Journal of Cryptology, 5(1), pp. 53–66, 1992.
136
The peculiar-looking constant is the (approximate) value of − lg(1 − c) where c ≈0.1100 is the real number in [0, 1/2] satisfying H2 (c) = 0.5 where H2 is the binary
entropy function, H2 (x) = −x lg x − (1 − x) lg(1 − x).
137
The sort of PRG that takes input and maintains state, which will now include abigkey. See: Boaz Barak, Shai Halevi: A model and architecture for pseudo-random
generation with applications to /dev/random. ACM CCS 2005. Yevgeniy Dodis,

The Moral Character of Cryptographic Work33

bigkey cryptography as one tool that cryptographers can contribute to makemass surveillance harder.
More examples. Here are a few more examples of crypto-for-privacy work.
Consider the beautiful paper on Riposte, by Corrigan-Gibbs, Boneh, andMazières.138 A user, speaking with others on the Internet, wants to broadcast a
message, such as a leaked document, without revealing his identity. The network
is subject to pervasive monitoring. The authors develop definitions, protocols,and proofs for the problem, attending closely to efficiency.139 They implement
their schemes. Combining all these elements is rare—and very much needed.140
Or consider the work of Colin Percival in which he introduced the hashfunction scrypt.141 Percival explained that, when applying an intentionallyslow-to-compute hash function to a password and salt so as to up the cost of
dictionary attacks,142 it is better if the hash function can’t be sped up all thatmuch with custom hardware. To achieve this aim, computing the hash function
shouldn’t just take lots of time, but lots of (sequentially accessed) memory. This
insightful idea comes from Abadi, Burrows, Manasse, and Wobber, who wanted
to make sure that, for a variety of settings, computing an intentionally-slow
hash function on a high-end system would take roughly as long as computing
it on a low-end system.143 Quite recently, a Password Hashing Competition
David Pointcheval, Sylvain Ruhault, Damien Vergnaud, Daniel Wichs: Security
analysis of pseudo-random number generators with input: /dev/random is notrobust. ACM CCS 2013.
138
Henry Corrigan-Gibbs, Dan Boneh, David Mazières: Riposte: An anonymous
messaging system handling millions of users. IEEE Symposium on Security andPrivacy, pp. 321–338, 2015.
139
The techniques come mostly from PIRs, the body of work to make PIRs more
efficient, and the recent notion of a distributed point function, from Gilboa and Ishai.
Benny Chor, Eyal Kushilevitz, Oded Goldreich, Madhu Sudan: Private information
retrieval. JACM 45(6), pp. 965–981, 1998. Earlier version from FOCS 1995.
Niv Gilboa, Yuval Ishai: Distributed point functions and their applications.
EUROCRYPT 2014, pp. 640–658.
140
Another recent paper that does a beautiful job at the nexus of systems, privacy,
and cryptography is: Nikita Borisov, George Danezis, Ian Goldberg: DP5: A private
presence service. Proceedings on Privacy Enhancing Technologies (PETS) vol. 2,
pp. 4–24, 2015. That paper again depends crucially on PIRs—this time for creating
a service to tell you—but not the service provider—which of your “friends” arecurrently online, using the same, Facebook-like service.
141
Colin Percival: Stronger key derivation via sequential memory-hard functions.
BSDCan’09, May 2009. http://www.tarsnap.com/scrypt/scrypt.pdf
142
The technique goes back to the UNIX crypt(3) functionality.
143
Martı́n Abadi, Mike Burrows, Mark Manasse, and Ted Wobber: Moderately hard,
memory-bound functions. ACM Trans. on Internet Technology, 5(2), pp. 299–327,
May 2005. Earlier version in NDS 2003. This paper includes a concrete construction
for a memory-hard hash function. An earlier proposal for a hash function
parameterized by both the time and space it should need is given in a proposal by

34

P. Rogaway(PHC) concluded having chosen a scheme, Argon2,144 that follows this lead.
Meanwhile, the theory for this sort of hash function has nicely progressed.145
While we don’t yet have good bounds on schemes like scrypt and Argon2, I
think we’re getting there.146
Or consider the paper on the susceptibility of symmetric encryption to mass
surveillance by colleagues and me.147 We discussed algorithm-substitution
attacks, wherein big brother replaces a real symmetric encryption algorithm
by a subverted one. Big brother’s aim is to surreptitiously decrypt all encrypted
traffic. The idea goes back to Young and Yung;148 all we did was to rigorously
explore the idea in the context of symmetric encryption. Yet what we found
was disturbing: that almost all symmetric encryption schemes can be easily
subverted. Still, we showed that it is easy to make schemes where this isn’t true.
And then there’s the Logjam paper, showing, for the umpteenth time, that
we must watch out for the cryptanalytic value of precomputation.149 Attacks
should routinely be regarded as a two-step process: an expensive one that
depends on widely shared parameters, then a cheaper, individualized attack.150
Such thinking goes back to early time-memory tradeoffs,151 and to many
cryptographer’s preference for nonuniform adversaries. It occurs in practical

Arnold Reinhold entitled HEKS: A Family of Key Stretching Algorithms, July 15,
1999 (revised July 5, 2001), http://world.std.com/ reinhold/HEKSproposal.html
144
Alex Biryukov, Daniel Dinu, Dmitry Khovratovich: Argon2. July 8, 2015.
https://www.cryptolux.org/index.php/Argon2
145
Joël Alwen and Vladimir Serbinenko: High parallel complexity graphs and memoryhard functions. STOC 2015, pp. 595–603.
146
Why is this topic crypto-for-privacy? First, it’s about helping individuals avoid
getting their accounts compromised. Second, for electronic currency, it helps keep
small-scale mining more cost-competitive with large-scale operations. That isn’t at
all true for bitcoin, where mining tends to be centralized and energy-intensive The
GHash.IO mining pool boasts on its website a mining rate of 6.35 Ph/s (252.5 hashes
per second), and the overall rate is about 465 Ph/s (258.7 hashes per second). Datataken from https://ghash.io/ and https://blockchain.info/charts/ on Nov. 1, 2015.
147
Mihir Bellare, Kenneth G. Paterson, and Phillip Rogaway: Security of symmetricencryption against mass surveillance. CRYPTO 2014.
148
Adam Young, Moti Yung: The dark side of black-box cryptography, or: should wetrust capstone? CRYPTO 1996. Adam Young, Moti Yung: Kleptography: using
cryptography against cryptography. EUROCRYPT 1997.
149
David Adrian, Karthikeyan Bhargavan, Zakir Durumeric, Pierrick Gaudry, Matthew
Green, J. Alex Halderman, Nadia Heninger, Drew Springall, Emmanuel Thomé,Luke Valenta, Benjamin VanderSloot, Eric Wustrow, Santiago Zanella-Béuelin,Paul Zimmermann: Imperfect forward secrecy: how Diffie-Hellman fails in practice.
Computer and Communications Security (CCS ’15), 2015.
150
Additionally, whenever possible, the active attack should be something that
detectable—something that requires interaction.
151
Martin Hellman: A cryptanalytic time-memory trade-off. IEEE Trans. on
Information Theory, 26(4), pp. 401–406, 1980.

The Moral Character of Cryptographic Work35

work, as in attacks on A5/1 in GSM phones.152 And it is also the model that
intelligence agencies seem to gravitate to, as suggested by the NSA’s attack on
FPE scheme FF2 and the fact that they regarded this attack as serious.153
Choose well. As I hope the examples I have given illustrate, there are important
crypto-for-privacy problems out there, and they are quite diverse. Choose yourproblems well. Let values inform your choice. Many times I have spoken to people
who seem to have no real idea why they are studying what they are. The realanswer is often that they can do it, it gets published, and that people did thisstuff before. These are lousy reasons for doing something.
Introspection can’t be rushed. In the rush to publish paper after paper, who
has the time? I think we should breathe, write fewer papers, and have themmatter more.
B Attend to problems’ social value. Do anti-surveillance research.
B Be introspective about why you are working on the problems you are.
In enumerating example directions for anti-surveillance research, I didn’t
include the kind of work, rather common in the PET (privacy-enhancing
technology) literature, that assumes that there will be pervasive collection, andthen tries to do what one can to minimize misuse.154 Since the immorality occurs
at the point of data collection, the aim here is to try to blunt the impact of thewrong already done. But it is hard to know how this plays out. I am concernedthat the work can play into the hands of those who seek technical support
for a position that says, in effect, “the collect-it-all approach is inevitable andonly temporarily problematic, for, once we figure this all out, privacy will behandled downstream, when the data is used.” But pervasive collection itself
chills free-speech and threatens liberal democracy, regardless of what one claims
will happen downstream.155
Practice-oriented provable security. It’s not just the topics we workon, but how we execute on them that shapes our field’s direction. For
nearly 25 years Mihir Bellare and I have developed that we call practiceoriented provable security. In a 2009 essay and talk,156 I discussed how various
inessential choices engendered a theory of cryptography that was less useful thannecessary. Today, I might number among the important historical choices (1) apreference for asymptotic analyses and theorems, and the correspondingly coarse
152

Karsten Nohl: Breaking GSM phone privacy. Black Hat USA 2010. Available on
youtube, URL https://www.youtube.com/watch?v=0hjn-BP8nro
153
Morris Dworkin, Ray Perlner: Analysis of VAES3 (FF2). Cryptology ePrint Archive
Report 2015/306. April 2, 2015. FPE stands for Format-Preserving Encryption.
154
See, for example, Seny Kamara: Restructuring the NSA metadata program. Financial
Cryptography Workshops 2014, pp. 235–247, 2014.
155
Reflecting this, the U.S. Fourth Amendment speaks not only of particularized
warrants being required for search, but also for seizure.
156
Phillip Rogaway: Practice-oriented provable security and the social construction of
cryptography. Manuscript, May 2009, and invited talk at Eurocrypt 2009.

36

P. Rogaway

conceptualizations of security with which this is paired; (2) a preference towards
minimalism, aesthetically construed, as a starting point for reductions; (3) the
dismissal of symmetric primitives and finite functions as targets of rigorous
inquiry; (4) a tradition of using nonconstructive language for stating results;(5) the marginalization of secure messaging; and (6) a condemnatory attitude
towards the random-oracle model, the random-permutation model, the idealcipher model, Dolev-Yao models,157 and any other model deemed non-standard.
Practice-oriented provable security inverts such choices. It retains provablesecurity’s focus on definitions and proofs, but these are understood as tools thatearn their value mostly by their utility to security or privacy. The approachis equally at home in those two realms, but it has been underused for privacy
problems like secure messaging. Better treating mix-nets and onion routing is
an obvious place to start, which students and I are doing.
B Apply practice-oriented provable security to anti-surveillance problems.
Funding.158 In the United States, it would seem that the majority of extramural
cryptographic funding may now come from the military.159 From 2000 to 2010,
fewer than 15% of the papers at CRYPTO that acknowledged U.S. extramuralfunding acknowledged DoD funding.160 In 2011, this rose to 25%. From 2012 to2015, it rose to 65%.161 Nowadays, many cryptographers put together a large
patchwork of grants, the largest of which are usually DoD. The following funding
acknowledgment isn’t so very atypical:

This work was supported by NSF, the DARPA PROCEED program, an
AFOSR MURI award, a grant from ONR, an IARPA project provided via
DoI/NBC, and by Samsung.162

157

Danny Dolev, Andrew C. Yao: On the security of public key protocols. IEEE Trans.
on Information Theory, IT-29, pp. 198–208, 1983.
158
This section deals exclusively with academic funding of cryptography in the U.S. I
know very little about cryptographic funding in other countries.
159
I have been unable to locate statistics on this.
160
DoD = Department of Defense. This includes organizations like AFOSR, IARPA,
DARPA, and ONR.
161
This data is based on an accounting I did myself, by hand, going through all theseold proceedings.
162
The acronyms are: AFOSR = Air Force Office of Scientific Research; DARPA =Defense Advanced Research Projects Agency; DoI/NBC = Department of Interior
National Business Center; IARPA = Intelligence Advanced Research Projects
Activity; MURI = Multidisciplinary University Research Initiative; NSF = National
Science Foundation; ONR = Office of Naval Research; and PROCEED =Programming Computation on Encrypted Data. Following the statement cameanother 35 words of legalistic language, including a statement that the paper had
been cleared “Approved for Public Release.” http://eprint.iacr.org/2013/403.pdf

The Moral Character of Cryptographic Work37

The military funding of science invariably redirects it163 and creates moral
hazards.164 Yet suggesting to someone that they might want to reconsider theirtaking DoD funding may anger even a placid colleague, for it will be perceived
as an assault both on one’s character and his ability to succeed.
No matter what people say, our scientific work does change in response tosponsor’s institutional aims. These aims may not be one’s own. For example,
the mission of DARPA is “to invest in the breakthrough technologies that cancreate the next generation of [U.S.] national security capabilities.” Having begunin the wake of Sputnik, the agency speaks of avoiding technological surprise—andcreating it for America’s enemies.165 In the USA, the NSA advises other DoD
agencies on crypto-related grants. At least sometimes, they advise the NSF. Backin 1996, the NSA tried to quash my own NSF CAREER award. I learned thisfrom my former NSF program manager, Dana Latch, who not only refused the
NSA request, but, annoyed by it, told me. An internal history of the NSA reportson the mistake of theirs that allowed funding the grant leading to RSA.
NSA had reviewed the Rivest [grant] application, but the wording was so
general that the Agency did not spot the threat and passed it back to NSF
without comment. Since the technique had been jointly funded by NSF and the
Office of Naval Research, NSA’s new director, Admiral Bobby Inman, visitedthe director of ONR to secure a commitment that ONR would get NSA’scoordination on all such future grant proposals.166

People are often happy to get funding, regardless of its source. But I would
suggest that if a funding agency embraces values inconsistent with your own,
then maybe you shouldn’t take their money. Institutions have values, no lessthan men. Perhaps, in the modern era, they even have more.
Large organizations have multiple and sometimes conflicting aims. Militaryorganizations with offensive and defensive roles in cybersecurity have COIs built
into their design. Individuals are wrong to assume that their work is non-military
work errantly funded by the military.
In his farewell address of 1961, President Dwight D. Eisenhower introduced
the phrase, and concept, of the military-industrial complex. In an earlier versionof that speech, Eisenhower tellingly called it the military-industrial-academic
complex.167 If scientists wish to reverse our complicity in this convergence ofinterests, maybe we need to step away from this trough.
None of this was clear to me when I first joined the university. A few years
ago I joined in on a DoD grant proposal (fortunately, unfunded), which I would
163

Daniel S. Greenberg: Science, Money, and Politics: Political Triumph and Ethical
Erosion. University of Chicago Press, 2003.
164
A moral hazard is a situation in which one party gets the benefits and another takes
the risk. The term is common in economics.
165
Darati Prabhakar: Understanding DARPA’s Mission. http://tinyurl.com/darpamission YouTube version http://tinyurl.com/darpa-mission2
166
Tom Johnson: Book III: Retrenchment and Reform, 1998. Formerly classified book,available, as a result of a FOIA request, at http://cryptome.org/0001/nsa-meyer.htm
167
Henry A. Giroux: The University in Chains: Confronting the Military-IndustrialAcademic Complex, Routledge, 2007.

38

P. Rogaway

not do today. It took me a long time to realize what eventually became obvious
to me: that the funding we take both impacts our beliefs and reflects on them.
In the end, a major reason that crypto-for-privacy has fared poorly may bethat funding agencies may not want to see progress in this direction,168 and mostcompanies don’t want progress here, either. Cryptographers have internalized
this. Mostly, we’ve been in the business of helping business and government
keep things safe. Governments and companies have become our “customers,” notsome ragtag group of activists, journalists, or dissidents, and not some abstract
notion of the people. Crypto-for-privacy will fare better when cryptographersstop taking DoD funds and, more than that, start thinking of a very different
constituency for our output.
B Think twice, and then again, about accepting military funding.169
B Regard ordinary people as those whose needs you ultimately aim to satisfy.
Academic freedom. Those of us who are academics at universities enjoy a
tradition of academic freedom. This refers to your right—and even obligation—to
think about, speak about, and write about whatever you want that is connected
to your work, even if it goes against the wishes of power: your university,
corporations, or the state. While academic freedom seems to be in decline,170 atleast for now, it recognizably persists.
Normally, scientists and other academics don’t actually need or use theiracademic freedom: all they really need is funding and skill.171 But crypto-forprivacy may be a rare topic where academic freedom is useful.172 I suggest thatpeople use this gift. Unexercised, academic freedom will wither and die.
Many nonacademics also have something akin to academic freedom: sufficientautonomy to work on what they think is important, without losing their jobs,
even if it’s not what their employer really wants or likes.
B Use the academic freedom that you have.
168

People will of course point to Tor as a counterexample; it has received funding fromDARPA, ONR, and the State Department. I don’t think there’s much to explain.
Every large bureaucracy has within it competing and conflicting directions. Somesegments of the U.S. government can think Tor is great even when others would liketo defund, dismantle, or subvert it.
169
In the USA, this means AFOSR, ARO, DARPA, IARPA, MURI, NSA, ONR, and
more.
170
Frank Donoghue: The Last Professors: The Corporate University and the Fate of the
Humanities. Fordham University Press, 2008. Or see: The Center for Constitutional
Rights and Palestine Legal: The Palestine exception to free speech: a movement
under attack in the US. Sep. 30, 2015. https://ccrjustice.org/the-palestine-exception
171
Lorren R. Graham: Money vs freedom: the Russian contradiction. Humanities, 20(5),Sept/Oct 1999.
172
For a description of an incident involving Matthew Green, see: Jeff Larson and Justin
Elliott: Johns Hopkins and the Case of the Missing NSA Blog Post. ProPublica,
Sep. 9, 2013. For a description of an incident at Purdue involving Barton Gellman,see his article: I showed leaked NSA slides at Purdue, so feds demanded the video
be destroyed. Ars Technica, Oct. 9, 2015. http://tinyurl.com/gellman-at-purdue

The Moral Character of Cryptographic Work

39

Against dogma. I think that many cryptographers would do well to foster amore open-minded attitude to unfamiliar models, approaches, and goals. The disciplinary narrowing within cryptography’s tier-1 venues has been pronounced.173
Many people seem to hold rather strident beliefs about what kinds of work aregood. Sometimes it borders on silliness, as when people refuse to use the word
proof for proofs in the random-oracle model. (Obviously a proof in the randomoracle model is no less a proof than a proof in any other model.)As cryptographers, we must always be sensitive, and skeptical, about therelationship between our models and actual privacy or security. This doesn’tmean that we should not take models seriously. It means that we should seethem as tentative and dialectical. There’s a lovely aphorism from statistician
George Box, who said that all models are wrong, but some are useful.174
Cryptography needs useful models. But the assessment of a model’s utility
is itself problematic. We ask of definitions: How clean? How understandable?
How general? What aspects of the computing environment are covered? What
does and doesn’t it imply? The definitional enterprise sits at a juncture of math,aesthetics, philosophy, technology, and culture. So situated, dogma is disease.
It has been claimed that the mission of theoretical cryptography is to define
and construct provably secure cryptographic protocols and schemes.175 But thisis an activity of theoretical cryptography, not its mission. There are many otheractivities. One might work on models and results that are completely rigorous but
fall outside of the provable-security framework.176 Or one can take an important
protocol as fixed and then analyze it, in whatever framework works best. The
aim for my own work has been to develop ideas that I hope will contributeto the construction of secure computing systems. In the symbology of Amit
Sahai’s lovely flower-garden,177 theory-minded cryptographers can be gardeners,
growing seeds (hardness assumptions) into flowers (cryptographic goals); but
173

For the most part, hardware is gone, formalistic approaches to cryptography are gone(unless they claim to bridge to “real” crypto), cryptanalysis of real-world schemesis little to be seen, and so on.
174
George E. P. Box: Robustness in the strategy of scientific model building. In: Launer,
R. L.; Wilkinson, G. N., Robustness in Statistics, Academic Press, pp. 201–236, 1979.
Box was not the first to express this sentiment. For example, Georg Rasch explained,
in 1960, that “When you construct a model you leave out all the details which you,with the knowledge at your disposal, consider inessential. . . . Models should not be
true, but it is important that they are applicable, and whether they are applicablefor any given purpose must of course be investigated. This also means that a modelis never accepted finally, only on trial.” Georg Rasch: Probabilistic models for someintelligence and attainment tests. Copenhagen: Danmarks Paedogogiske Institut,
pp. 37–38, 1960. republished by University of Chicago Press, 1980.
175
Shafi Goldwasser, Yael Tauman Kalai: Cryptographic assumptions: a position paper.
Cryptology ePrint Archive Report 2015/907, Sep. 16, 2015.
176
The entire information-theoretic tradition of cryptography is in this vein.
177
Amit Sahai: Obfuscation II. Talk at the Simons Institute. May 19, 2015. Available
at https://simons.berkeley.edu/talks/amit-sahai-2015-05-19b

40

P. Rogaway

they can do many other things as well. Which is fortunate, as cryptographic
practice hasn’t benefited all that much from our horticultural activities.
B Be open to diverse models. Regard all models as suspect and dialectical.
A more expansive view. I would encourage cryptographers—especially young
people in our field—to try to get a systems-level view of what is going on when
cryptography is used. You need a way better view of things than a technophobe
like me will ever have.
I remember reading that 2012 paper of Dan Boneh and his coauthors, The
Most Dangerous Code in the World,178 and feeling humbled by the fact that
there was this entire universe of code—this middleware—that I didn’t even know
existed, but that could, and routinely did, annul the cryptography that wasthere. When the NSA revelations caused people to speculate as to how Internet
cryptography was being defeated, it occurred to me that perhaps the NSA didn’t
need any clever cryptanalysis—what they needed, most of all, was to buy exploits
and hire people with a systems-level view of the computing ecosystem.
One approach that might be useful for gaining a good vantage is to take an
API-centric view of things.179 Not only are API misunderstandings a common
security problem, but gaps between cryptographic formalizations and APIs can
produce serious cryptographic problems.180 And in the constructive direction,
the notion of online-AE, for example,181 effectively flows from taking an APIcentric view. APIs and “serious” cryptography need stronger bonds.
Research communities have a general tendency to become inward-looking. As
a community, we have fostered strong relationships to algorithms and complexity
theory, but have done less well attending to privacy research, programming
languages, or the law. We will play a larger social role if we up our connections
to neighbors.
I recently saw a nice talk by Chris Soghoian in which he described hisfrustration in trying to get media to report on, or anyone else to care about, thewell-known fact (that is actually not well known) that cell-phone conversations
have essentially no privacy.182 Cryptographers should be helping with such
178

Martin Georgiev, Subodh Iyengar, Suman Jana, Rishita Anubhai, Dan Boneh, Vitaly
Shmatikov: The most dangerous code in the world: validating SSL certificates in nonbrowser software. ACM Conference on Computer and Communications Security,
pp. 38–49, 2012.
179
API is application programming interface, the architected interfaces among
component code.
180
Serge Vaudenay: Security flaws induced by CBC padding: applications to SSL,IPSEC, WTLS . . .. Eurocrypt 2002.
181
Viet Tung Hoang, Reza Reyhanitabar, Phillip Rogaway, Damian Vizár: Online
authenticated-encryption and its nonce-reuse misuse-resistance. Crypto 2015, vol. 1,
pp. 493–517, 2015. Guido Bertoni, Joan Daemen, Michaël Peeters, Gilles Van Assche:
Duplexing the sponge: single-pass authenticated encryption and other applications.
Selected Areas in Cryptography 2011, pp. 320–337, 2011.
182
Chris Soghoian, Workshop on Surveillance and Technology (SAT 2015), Drexel
University, June 29, 2015. See also: Chris Soghoian: How to avoid surveillance. . .with

The Moral Character of Cryptographic Work41

communications. But I wonder how much we have even paid attention. For mostof us, if it’s not what one’s working on, one doesn’t really care. There isn’t time.
B Get a systems-level view. Attend to that which surrounds our field.
Learn some privacy tools. I would like to gently suggest that we cryptographers would do well to learn, and use, contemporary privacy tools. Very few of us
use tools like OTR, PGP, Signal, Tails, and Tor. It’s kind of an embarrassment—
and I suspect our collective work suffers for it. Christopher Soghoian insightfully
remarks: “It’s as if the entire academic medical community smoked 20 cigarettes
a day, used intravenous drugs with shared needles, and had unprotected sex withrandom partners on a regular basis.”183
I’m a bizarre person to advocate in this direction—it’s definitely a case of the
pot calling the kettle black. I am dispositionally uninterested in using technology,
and am incompetent at doing so if I try. I don’t even own a smartphone. Yet
I suspect that there is nothing like experience to motivate cryptographers to
identify and solve the privacy problems that will help us to transform hard-touse tools for nerds into transparently embedded mechanisms for the masses. The
first problem I suggested in Section 4 is something I thought of within days ofstarting to use Pond.
B Learn some privacy tools. Use them. Improve them.
No cutesy adversaries. There is a long tradition of cutesiness in our field.
People spin fun and fanciful stories. Protocol participants are a caricatured Aliceand Bob. Adversaries are little devils, complete with horns and a pitchfork. Some
crypto talks are so packed with clip-art you can hardly find the content. I havenever liked this, but, after the Snowden revelations, it started to vex me likenever before.
Cryptography is serious, with ideas often hard to understand. When we try
to explain them with cartoons and cute narratives, I don’t think we make ourcontributions easier to understand. What we actually do is add in a layer ofobfuscation that must be peeled away to understand what has actually been
done. Worse, the cartoon-heavy cryptography can reshape our internal visionof our role. The adversary as a $53-billion-a-year military-industrial-surveillancecomplex and the adversary as a red-devil-with-horns induce entirely different
thought processes. If we see adversaries in one of these ways, we will actually
your phone. TED talk. https://www.youtube.com/watch?v=ni4FV5zL6lM.
Stephanie K. Pell and Christopher Soghoian: Your secret Stingray’s no secret
anymore: the vanishing government monopoly over cell phone surveillance and its
impact on national security and consumer privacy. Harvard Journal of Law andTechnology, 28(1), Fall 2014.
183
Christopher Soghoian, personal communications, Nov. 28, 2015.

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P. Rogaway

see at a different set of problems to work on than if we see things in the other.
Whimsical adversaries engender a chimerical field.184
As a graduate student, I wanted our field to feel fantastical. I wanted a
discipline full of space aliens and communicating millionaires. Not only was it
fun, but it stroked my ego, effectively embodying the sentiment: I am a scientist
too smart to have to deal with small-minded concerns.
At this point, I think we would do well to put ourselves in the mindset of areal adversary, not a notional one: the well-funded intelligence agency, the profitobsessed multinational, the drug cartel. You have an enormous budget. You
control lots of infrastructure. You have teams of attorneys more than willing tointerpret the law creatively. You have a huge portfolio of zero-days.185 You have amountain of self-righteous conviction. Your aim is to Collect it All, Exploit it All,
Know it All.186 What would frustrate you? What problems do you not want abunch of super-smart academics to solve?
B Stop with the cutesy pictures. Take adversaries seriously.
A cryptographic commons. Many people see the Internet as some sort ofmagnificent commons. This is a fantasy. There are some successful commons
within the Internet: Wikipedia, the free software movement, Creative Commons,
OpenSSL, Tor, and more. But most people turn almost exclusively to services
mediated by a handful of corporations that provide the electronic mail, instantmessaging, cloud storage, and cloud computing, for example, that people use.
And they provide the hardware on which all this stuff sits.
We need to erect a much expanded commons on the Internet. We need torealize popular services in a secure, distributed, and decentralized way, poweredby free software and free/open hardware. We need to build systems beyond thereach of super-sized companies and spy agencies. Such services must be basedon strong cryptography. Emphasizing that prerequisite, we need to expand our
cryptographic commons.
Dreams for such a commons go back to the cypherpunks, who built remailers,for example, as a communitarian service to enable secure communications. Morerecently, Feigenbaum and Koenig articulate such a vision.187 After explainingthat centralized cloud services play a central role in enabling mass surveillance,
they call for a grass-roots effort to develop new, global-scale cloud services basedon open-source, decentralized, configuration-management tools.
184

Despite all these comments, I think a graphic novel on cryptography could be great.
Something like the work of Keith Aoki, James Boyle: Bound By Law: Tales from the
Public Domain, 2006.
185
Exploits that nobody else knows about.
186
The phrases are from an NSA slide released by Snowden. Reprinted on p. 97 of Glenn
Greenwald: No Place to Hide: Edward Snowden, the NSA, and the U.S. SurveillanceState, 2014.
187
Joan Feigenbaum, Jérémie Koenig: On the feasibility of a technological response to
the surveillance morass. Security Protocols Workshop 2014, pp. 239–252, 2014.

The Moral Character of Cryptographic Work43

We might start small by doing our piece to improve the commons we do have:
Wikipedia. It could become a routine undertaking at IACR conferences andworkshops, or at Dagstuhl meeting, for folks to gather around for an afternoon
or evening to write, revise, and verify selected Wikipedia pages dealing withcryptography. It’s the sort of effort that will pay off in many unseen ways.
B Design and build a broadly useful cryptographic commons.
Communications. In advancing our field, well-named notions have always been
important. One has only to think back to zero-knowledge (and the competing
term minimal-disclosure) to recall how a beautiful phrase could help catapult
a beautiful idea into prominence. Similarly, the six-letter phrase 33 bits doesa remarkably good job of embodying an important concept without going
anywhere near contested vocabulary.188 In both cryptography and privacy,
language is both formative and fraught.
The word privacy, its meaning abstract and debated, its connotations often
negative, is not a winning word. Privacy is for medical records, toileting, andsex — not for democracy or freedom. The word anonymity is even worse: modern
political parlance has painted this as nearly a flavor of terrorism. Security ismore winning a word and, in fact, I spoke of secure messaging instead of private
messaging or anonymous messaging because I think it better captures what I
want conveyed: that a communication whose endpoints are manifest is not at all
secure. A person needs to feel insecure if using such a channel.
But even the word security doesn’t support a good framing of our problem:
we should try to speak of thwarting mass surveillance more than enhancing
privacy, anonymity, or security. As discussed before, we know instinctively
that ubiquitous surveillance is incompatible with freedom, democracy, andhuman rights.189 This makes surveillance a thing against which one can fight.
The surveillance camera and data center make visual our emerging dystopia,
while privacy, anonymity, and security are so abstract as to nearly defy visual
representation.
Concretely, research that aims to undermine objectionable surveillancemight be called anti-surveillance research.190 Tools for this end would be antisurveillance technologies.191 And choosing the problems one works on based onan ethical vision might be called conscience-based research.
B Choose language well. Communication is integral to having an impact.
188

The value refers, of course, to the number of bit needed to identify a living human.
See Arvind Narayanan’s website 33bits.org
189
For a beautiful exposition of this idea, see Eben Moglen: Privacy under attack: the
NSA files revealed new threats to democracy. The Guardian, May 27, 2014. The
article is derived from the four-part lecture: Eben Moglen: Snowden and the future,delivered Oct. 9, Oct. 30, Nov. 13, and Nov. 4, 2013, the Columbia Law School.
http://snowdenandthefuture.info/
190
This suggestion, as well as conscience-based research, are from Ron Rivest.
191
While the term is already in use, the more customary term of art is privacy-enhancing
technologies.

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P. Rogaway

Institutional values. This essay might seem to focus on the ethical weight ofeach scientist’s personal, professional choices. But I am actually more concerned
about how we, as cryptographers and computer scientists, act in aggregate. Ourcollective behavior embodies values—and the institutions we create do, too.
I do not intend to criticize any particular individual. People should and will
work on what they think to be most valuable. The problem occurs when ourcommunity, as a whole, systematically devalues utility or social worth. Then we
have a collective failure. The failure falls on no one in particular, and yet it falls
on everyone.
Conclusion to it all. Many before me have discussed the importance of ethics,
disciplinary culture, and political context in shaping what we do. For example,
Neal Koblitz asserts that the founding of the CRYPTO conference in 1981 wasitself an act of defiance. He warns of the corrupting role that funding can play.
And he concludes his own essay with an assertion that drama and conflict are
inherent in cryptography, but that this also makes for some of the field’s fun.192
Susan Landau reminds us that privacy reaches far beyond engineering, and into
law, economics, and beyond. She reminds us that minimizing data collection ispart of the ACM Code of Ethics and Professional Conduct.193
As computer scientists and cryptographers, we are twice culpable when it
comes to mass surveillance: computer science created the technologies that
underlie our communications infrastructure, and that are now turning it into
an apparatus for surveillance and control; while cryptography contains within it
the underused potential to help redirect this tragic turn.194
Authors and filmmakers, futurists and scientists, have laid out many
competing visions for man’s demise. For example, Bill Joy worries about
nanotechnology turning the biosphere into gray goo, or super-intelligent robots
deciding that man is a nuisance, or a pet.195 I don’t lose sleep over suchpossibilities; I don’t see them as our likely end. But a creeping surveillance thatgrows organically in the public and private sectors, that becomes increasingly
comprehensive, entwined, and predictive, that becomes an instrument forassassination, political control, and the maintenance of power—well, this vision
doesn’t merely seem possible, it seems to be happening before our eyes.
I am not optimistic. The figure of the heroic cryptographer sweeping in tosave the world from totalitarian surveillance is ludicrous.196 And in a world where
192

Neal Koblitz: The uneasy relationship between mathematics and cryptography.
Notices of the AMS, 54(8), pp. 972–979, September 2007.
193
Susan Landau: Privacy and security: a multidimensional problem. Communicationsof the ACM, 51(11), November 2008.
194
Of course we cryptographers are not the only ones in the thick of this. People whowork on “data science” and “big data” are especially involved.
195
Bill Joy: Why the future doesn’t need us. Wired, 8.04. April 2000.
196
That said, there is considerable drama in the experiences of people like Julian
Assange, William Binney, William Davidon, Tom Drake, Daniel Ellsberg, Mark
Klein, Annie Machon, Chelsea Manning, Laura Poitras, Jesselyn Radack, Diane
Roark, Aaron Swartz, Edward Snowden, and J. Kirk Wiebe.

The Moral Character of Cryptographic Work45

intelligence agencies stockpile and exploit countless vulnerabilities, obtain CA
secret keys, subvert software-update mechanisms, infiltrate private companies
with moles, redirect online discussions in favored directions, and exert enormous
influence on standards bodies, cryptography alone will be an ineffectual response.
At best, cryptography might be a tool for creating possibilities within contours
circumscribed by other forces.
Still, there are reasons to smile. A billion users are getting encrypted instantmessaging using WhatsApp and its embedded Axolotl protocol.197 Two million
clients connect using Tor each day.198 Cryptography papers inspired by the
Snowden revelations are starting to come out apace. More than 50 crypto
and security researchers from the U.S.A. signed an open letter I co-organized
deploring society-wide surveillance.199 The 15-author Keys Under Doormats
report200 is an explicit attempt to have cryptographic expertise inform policy.
And it’s not as though crypto-for-privacy is something new or deprecatedwithin our community. Cryptographers like Ross Anderson, Dan Bernstein, Matt
Blaze, David Chaum, Joan Feigenbaum, Matt Green, Nadia Heninger, Tanja
Lange, Arjen Lenstra, Kenny Paterson, Ron Rivest, Adi Shamir, Nigel Smart,and Moti Yung, to name just a few, have been attending to practical privacy
long before it started to get trendy (if this is happening). The RWC (Real World
Cryptography) conference is creating a new and healthy mix of participants.
Talks, workshops, and panel discussions on mass surveillance are helping
cryptographers see that dealing with mass surveillance is a problem within our
discipline. Bart Preneel and Adi Shamir have been going around giving talks
entitled Post-Snowden Cryptography, and there were panel discussions with thistitle at Eurocrypt 2014 and RSA-CT 2015.
Articles are emerging with titles like “Cryptographers have an ethics
problem.”201 When an attack on Tor by CMU researchers was allegedly used
197

Moxie Marlinspike and Trevor Perrin: The TextSecure Ratchet (webpage).
Nov. 26, 2013. https://whispersystems.org/blog/advanced-ratcheting/. User numbers available at URL http://www.statista.com/statistics/260819/number-ofmonthly-active-whatsapp-users/
198
Data from https://metrics.torproject.org/userstats-relay-country.html, 2014-11-01
to 2015-11-29.
199
An open letter from US researchers in cryptography and information security.
Jan. 24, 2014. http://masssurveillance.info/
200
H. Abelson, R. Anderson, S. M. Bellovin, J. Benaloh, M. Blaze, W. Diffie,
J. Gilmore, M. Green, S. Landau, P. G. Neumann, R. L. Rivest, J. I. Schiller,
B. Schneier, M. Specter, D. J. Weitzner: Keys under doormats: mandating insecurity
by requiring government access to all data and communications (2015). Available at
http://www.crypto.com/papers/Keys Under Doormats FINAL.pdf. 2015. Earlier,related report: H. Abelson, R. Anderson, S. M. Bellovin, J. Benaloh, M. Blaze,
W. Diffie, J. Gilmore, P. G. Neumann, R. L. Rivest, J. I. Schiller, B. Schneier:
The risks of key recovery, key escrow, and trusted third-party encryption (1997).
Available at http://academiccommons.columbia.edu/catalog/ac:127127
201
Antonio Regalado: Cryptographers have an ethics problem. MIT Technology Review.
Sep. 13, 2013. John Bohannon: Breach of trust. Science Magazine, 347(6221), Jan. 30,
2015.

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P. Rogaway

to provide bulk anonymized data to the FBI, CMU and the researchers involved
were publicly shamed.202 The IACR itself has been getting more vocal, bothwith the Copenhagen Resolution203 and the statement on Australia’s Defence
Trade Controls Act.204
While our community has embraced crypto-for-privacy less than I would like,this has been a cultural issue—and culture can change.
I have heard it said that if you think cryptography is your solution, you don’t
understand your problem.205 If this quip is true, then our field has gone seriously
astray. But we can correct it. We need to make cryptography the solution to the
problem: “how do you make surveillance more expensive?”
Dan Bernstein speaks of interesting crypto and boring crypto. Interesting
crypto is crypto that supports plenty of academic papers. Boring crypto
is “crypto that simply works, solidly resists attacks, [and] never needs any
upgrades.” Dan asks, in his typically flippant way,
What will happen if the crypto users convince some crypto researchers toactually create boring crypto?
No more real-world attacks. No more emergency upgrades. Limited audience
for any minor attack improvements and for replacement crypto.
This is an existential threat against future crypto research.206

If this is boring crypto, we need to go do some.
Cypherpunk cryptography has been described as crypto with an attitude.207
But it is much more than that, for, more than anything else, what the
cypherpunks wanted was crypto with values. And values, deeply felt and deeply202

Tor security advisory: “relay early” traffic confirmation attack. July 30, 2014.
http://tinyurl.com/tor-attack1. Tor project blog: Did the FBI pay a university
to attack Tor users? Nov. 11, 2015. http://tinyurl.com/tor-attack2. This article
included: “Whatever academic security research should be in the 21st century, itcertainly does not include ‘experiments’ for pay that indiscriminately endanger
strangers without their knowledge or consent.” Also see reaction like: Joe Papp: The
attempt by CMU experts to unmask Tor project software was appalling. Pittsburgh
Post-Gazette. Aug. 5, 2014. http://tinyurl.com/papp-letter
203
The statement, adopted May 14, 2014 at the business meeting in Copenhagen,Denmark, says: The membership of the IACR repudiates mass surveillance and theundermining of cryptographic solutions and standards. Population-wide surveillance
threatens democracy and human dignity. We call for expediting research anddeployment of effective techniques to protect personal privacy against governmental
and corporate overreach. https://www.iacr.org/misc/statement-May2014.html
204
See https://www.iacr.org/petitions/australia-dtca/
205
According to Butler Lampson (personal communications, Dec. 2015), the quote(or one like it) is from Roger Needham. Yet Needham, apparently, used toattribute it to Lampson: Ross Anderson: Security Engineering: A Guide to Building
Dependable Distributed Systems, p. 367, 2008, http://www.cl.cam.ac.uk/∼rja14/
Papers/SE-18.pdf
206
Dan Bernstein: Boring crypto. Talk at SPACE 2015. Malaviya National Institute ofTechnology, Jaipur. Slides and audio at http://cr.yp.to/talks.html
207
Steven Levy: Crypto rebels. Wired, Feb. 01, 1993.

The Moral Character of Cryptographic Work47

embedded into our work, is what the cryptographic community needs most. And
perhaps a dose of that cypherpunk verve.208
It has been said that just because you don’t take an interest in politics,
doesn’t mean politics won’t take an interest in you.209 Since cryptography is atool for shifting power, the people who know this subject well, like it or not,inherit some of that power. As a cryptographer, you can ignore this landscape of
power, and all political and moral dimensions of our field. But that won’t makethem go away. It will just tend to make your work less relevant or socially useful.
My hope for this essay is that you will internalize this fact and recognize it
as the starting point for developing an ethically driven vision for what you wantto accomplish with your scientific work.
I began this essay speaking of the Russell–Einstein manifesto, so let me end
there as well, with Joseph Rotblat’s plea from his Nobel prize acceptance speech:
At a time when science plays such a powerful role in the life of society, when
the destiny of the whole of mankind may hinge on the results of scientificresearch, it is incumbent on all scientists to be fully conscious of that role, andconduct themselves accordingly. I appeal to my fellow scientists to remember
their responsibility to humanity.210

Acknowledgments
My thanks go first to Mihir Bellare for countless discussions on the topic of thisessay. For years, not only have we collaborated closely on technical matters, but
we have also much discussed the values and sensibilities implicitly embedded
within cryptographic work. Without Mihir, not only would I have done far lesstechnically, but I would also understand far less about who cryptographers are.
Ron Rivest not only provided useful comments, but has been much on mymind as I have agonized over this essay. Many other people have given me
important suggestions and ideas. I would like to thank Jake Appelbaum, Ross
Anderson, Tom Berson, Dan Boneh, David Chaum, Joan Feigenbaum, Pooya
Farshim, Seda Gürses, Tanja Lange, Chip Martel, Stephen Mason, Chanathip
Namprempre, Ilya Mironov, Chris Patton, Charles Raab, Tom Ristenpart,
Amit Sahai, Rylan Schaeffer, Adi Shamir, Jessica Malekos Smith, Christopher
Soghoian, Richard Stallman, Colleen Swanson, Björn Tackmann, Helen Thom,
208

John Perry Barlow: A declaration of the independence of cyberspace. Feb. 8,
1996. Eric Hughes: A cypherpunk’s manifesto. March 9, 1993. Timothy May: The
cyphernomicon. Sept. 10, 1994. Aaron Swartz: Guerilla open access manifesto. July
2008.
209
Barry Popik indicates that the quote “has been attributed to Greek leader Pericles(495–429 BC), but only since the late 1990s. The Greek source is never identified in
the frequent citations. The quotation appears to be of modern origin.” Blog entry,
June 22, 2011. http://tinyurl.com/not-pericles
210
Joseph Rotblat: Remember Your Humanity. Acceptance and Nobel lecture, 1995.
Text available at Nobelprize.org

48

P. Rogaway

Jesse Walker, Jacob Weber, and Yusi (James) Zhang for their comments,
discussions, and corrections.
My view of what science is and what the scientist should be was strongly
shaped by watching Jacob Bronowski when I was a child.211
All original technical work mentioned in this essay (e.g., what is describedin the first pages of Part 4) was supported by NSF Grant CNS 1228828. But I
emphasize that all opinions, findings, conclusions and recommendations in thisessay (and this essay is mostly opinions and recommendations) reflect the viewsof the author alone, not necessarily the views of the National Science Foundation.
Thanks to the Schloss Dagstuhl staff and to the participants of workshop
14401, Privacy and Security in an Age of Surveillance, where ideas related tothis essay were discussed.212
Some of the work on this essay was done while I was a guest professor at
ENS, Paris, hosted by David Pointcheval.
My thanks to the IACR Board for the privilege of giving this year’s
IACR Distinguished Lecture. It is an honor that happens at most once in a
cryptographer’s career, and I have tried my best to use this opportunity wisely.
This essay owes its existence to the courage of Edward Snowden.

211
212

Jacob Bronowski: The Ascent of Man. TV series. BBC and Time-Life Films, 1973.
Bart Preneel, Phillip Rogaway, Mark D. Ryan, and Peter Y. A. Ryan: Privacy andsecurity in an age of surveillance (Dagstuhl perspectives workshop 14401). Dagstuhl
Manifestos, 5(1), pp. 25-37, 2015.