From: bontchev@fbihh.informatik.uni-hamburg.de (Vesselin Bontchev)
Subject: Re: Zimmermann's responses to Sidelnikov's PGP critique
Reply-To: bontchev@fbihh.informatik.uni-hamburg.de
Organization: Virus Test Center, University of Hamburg
Date:  8 Jan 93 22:28:57 GMT

strnlght@netcom.com (David Sternlight) writes:

> My purpose in posting this is not to enter into the dispute between
> Zimmermann and Sidelnikov, but to comment on some interesting questions that
> the Sidelnikov post may raise. Some preface may be in order:

As usual, David Sternlight is breaking in in a purely technical
discussion to introduce Fear, Uncertanity and Doubt with his
incompetent comments.

> In my many individual visits to the Soviet Union at the personal
> invitation of the Soviet Academy of Sciences, and in my discussions
> with Soviet scientific leaders, it became clear to me that in the
> Soviet structure, the academic and Academy scientific structure was
> intimately bound up with the military and intelligence structure.

It is/was more bound up with the communist party, although the
military also had a strong influence... Although, it is more exact to
say that it was the other way around - for instance, not the military
controled the schools, but the schools were organized a bit in a
military manner. To an inexperienced external observer it could indeed
look like if the military is controlling them...

> Through the mechanism of the State Committee on Science and Technology
> the Soviets ran their Nuclear, Missile, and many other programs.

Of course, the high-tech technologies had to be based on Science and
Technology. It is more than natural that SCST was used to control
them. And, as far as I know, the former USSR is not the only country
that uses the Science and Technology to produce nuclear weapons and
missils...

> Leaders in the State Committee were also leaders in the Soviet Academy
> of Sciences and in the academic community.

Which does not mean that they were all military spies, mind you. But
they were all members of the communist party - this was a
requirement.

> This raises the question of whether Sidelnikov had some senior role,
> directly or indirectly, in the Soviet's equivalent of the NSA. If he
> did, then his comments may be both authoritative with respect to
> access to what once was highly classified technology in the USSR,
> and (by the argument of parallelism) revelatory of the state of
> technology at the NSA.

:-)))). If he were, he wouldn't say a peep about any found
deficiencies in PGP, rest assured...

> >>    The MSU   mathematical   cryptography   problems   laboratory
> >>employeers with  some  addition  specialists  were  executed  the
> >>preliminary analysis of PGP ver.2.0 program.

> Is this lab a former part of the Soviet NSA? If so, one may assume

:-))))). No, it isn't. MSU stays for Moscow State University.

> a very high level of expertise, which gives major weight to what
> Sidelnikov says. We know that many intelligence specialists in
> Russia are now under- or unemployed and looking for work in
> the Western community. Thus it would not be surprising for Sidelnikov
> to "go public" as it were.

You are underestimating the level of paranoia in these circles...
Rest assured, if he were somehow connected with the people you
suspect, he wouldn't say anything publicly...

> >>infected by "virus"  which  intercept  confidential   keys   and 
> >>passwords used for  their protection and save them onto magnetic 
> >>carriers;
> >
> >The PGP manual warns of this problem.  A well-designed virus could
> >defeat any self-checking logic by attacking the self-checking logic.
> >It would create a false sense of security if PGP claimed to check
> >itself for viruses when you run it.

> Maybe Sidelnikov is trying to tell us something here that goes beyond
> the theoretical.

Now, I -am- an expert on computer viruses and with all my authority on
the subject I am stating that you are speaking nonsense.

> >>    - the program has not  optimal  exponentiation  algorithm  in
> >>GF(P) field,   when  P  -  prime  number,  which  result  in  low
> >>performance;
> >
> >PGP is freeware.  Maybe the exponentiation is not as optimal as it
> >could be if the PGP development effort were funded.  In any case,
> >improvements in the math algorithms have made PGP 2.0 faster than
> >version 1.0, and version 2.1 is faster still.  Of course, suggestions
> >for improving the performance of the algorithms are always welcome.

> Is Sidelnikov saying more than that the exponentiation isn't as fast
> as possible? Is he, perhaps, saying something about cryptographic
> weakness?

No, in the paragraph quoted by you he is speaking about an ineffective
implementation. He also mentioned something about a cryptographic
weakness (like the keys being easier to factor), but that was in a
different place.

> >>    - the prime numbers reception using in this program (R and  q
> >>in RSA  algorithm)  permits  not less than on two order to reduce
> >>the labour-intensiveness of factorization;  with 256 bit blocks
> >>of  data lenght it is possible to execute the cryptanalysis in
> >>real time;
> >
> >I don't know what this means.  PGP does not normally work with RSA
> >keys as small as 256 bits.  No claims are made that this is a safe
> >key length.  Larger RSA keys are specifically recommended in the
> >manual.  And what does "real time" mean in this case?

> If Sidelnikov says real time, he means real time. I take this to mean
> that the Russians, and the NSA can do the factorization and read RSA
> traffic with 256 bit keys in real time. If NSA's technology is better
> than the Russians, maybe they can read even longer key traffic so
> quickly as to make no difference. It would be interesting to see a
> calculation (Phil?) which, assuming 256 bit keys can be read in real
> time (call it a difficulty factor of 1.0), presents the difficulty
> factors for 512 and 1024 bit keys.

256 bits means 77-digit numbers. Hey, even I am able to factor such
thing with a workstation and a good factoring program! But, as Phil
said, PGP never uses such small keys... The smallest ones are 384-bit.

> This attitude is a hiding behind "academic" practice in an area where
> Sidelnikov has raised the most serious doubts about a number of
> aspects of PGP as presently implemented. For him to be both an

Sidelnikov expressed some doubts without backing them up with evidence
or explanations. It is more than normal to ask for proofs.

> Let me be perfectly clear here. Sidelnikov's standing in the
> cryptology field in the Soviet scientific community is of the most
> senior level, and that's not a statement about science politics. It's
> also likely he was (is?) either one of the most senior scientists in the
> former KGB cryptanalysis activity, or one of their most senior
> advisors.

If he were, he wouldn't be publishing his results...

> It's inappropriate to take his remarks as if they were those of some
> competitive programmer picking nits about PGP's program code.  It's

But it is perfectly appropriate to ask somebody to back up their
claims with evidence.

> Phil rethink this. I also suggest that Sidelnikov's advice about the
> use of PGP be heeded. Were I going to use it, I'd use no less than a
> 1024 bit key, and even then worry about some of the other weaknesses.

And I thought that you would not use PGP because you find it illegal,
unethical, immoral, fattening (oops, this does not belong here) and
whatnot... :-) Anyway, we need some proofs before discarding a
perfectly looking program, based on well-researched methods.

> Finally, I'd suggest extreme politeness in responding to Sidelnikov,
> and no little respect. Think of him as the Russian equivalent of
> Einstein in his field if it will help. In Soviet Science, Academicians
> are analogous to "the immortals".

:-))))). My guess is that either the word "academician" was not used
correctly, or that Dr. Sidelnikov is presenting the results achieved
by his laboratory, not by him... I just cannot believe that an
academician will spend time playing with such things... I also find it
hard to believe that an academician is only a lab manager... Maybe the
person who forwarded the message could clear that for us?

Regards,
Vesselin
-- 
Vesselin Vladimirov Bontchev          Virus Test Center, University of Hamburg
Tel.:+49-40-54715-224, Fax: +49-40-54715-226      Fachbereich Informatik - AGN
< PGP 2.1 public key available on request. > Vogt-Koelln-Strasse 30, rm. 107 C
e-mail: bontchev@fbihh.informatik.uni-hamburg.de    D-2000 Hamburg 54, Germany