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REF ID:A62859 

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As I said at the close ot tbe preceding lecture, a bit ot hiatory is 

alway& useful 1n introd.uciDg a subject belonging to a special am not too 

well knoWll field; therefore, I'll proceed with some hietorical intormtion 

about crwtology, which, aa you learned betore, compri•e• tvo closely 

related aciences, namely, cryptography and (:ryptanaJ yaie. I will repeat 

and e:mphaeize that they &I"e but opposite f'acea o't the same valuable coin; 

progress in one dnevitably lea4a to progreaa in the other, and to be 

et1'1c1ent in cryptology you auat know something about each of thea. 

Cryptography and cryptanalysis probably So back to the dt.wn ot the 

invention and developaent or the art of writing itself'. ID fact, tbere 

is reaaou for speculating u to which ca.- fix'•t--tbe invention ot writ11ig 

or the invention ot ceyptograpbyJ it •s aomewbat like the question aa to 

which came tirat--the hen or the egg. It 18 poHible that aom phuea ot 

cryptograpby cam before the art ot writing ha4 advanced very far. 

I've mentioned the art ot writtnc. As in the cue ot other aeem1ngly 

simple questions, such u, "why ia gru11 sreent", when we are asked to 

define writing we can •t tind a very 111.m,ple answer, Juat because the answer 

ian•t at all a1mple. Yet, Breasted, the famous Univera1ty ot Chicaao 

historian and Orientalist, once aai4: "The invention or writing and of a 

convenient l)'Btem ot records on J».per baa m4 a greater 1.nf'luence in 

uplittiJJ& tl:ae humn race than 8l1Y' other intellectual achievement 1J'l the 
/ 

REF ID:A62859 e 

career ot man." There bas been, 1n 'llf¥ humble op1uion, no gi-eater invention 

in all histoey. 'rhe invention of writing formed the real beg:ton1ng of 

civilization. AB laoguage distinguiabea nan from other an1•Js, so wr1t1Dg 

distiDgUishea civilized man from barbarian. To put the mtter briefly, 

writing exists only in a civilization aDd a oivillzati<m camwt exist without 

writing. Let ne rem1J¥l you tbat animla and 1.Dsects d.o cammunicate--tbere'a 

no question about that; but writiug u a thiug peculiar to am toum only as 

a phenareoon in which mn am no animl or insect eDg&Ses, an4 let's mver 

forget tbis fact. Mankilld lived and tunctioned tor an enormous number ot 

centuries before writillg was discovered and there is no doubt that writing 

was preceded. by articulate speech tor eona--but civilization beS&D only 

when men got the idea of am invented tbe art of writing. So tar aa concerns 

Western or Occidental civilization, writing 1D essence 1a a means of repreeenting the sounds of what ve call speech or apoken laDSuas-· Other ayatems 

ot writing were and some still are ban41capped by trying to represmat thiDsS 

and ideas by pictures. I'm being a bit solemn about tbia great invention 

because I want to impreaa upon you vb&t our studies 1n cryptoloa are raJ.ly 

intemled to do, namely, to defeat the buic or 1Dtended purpose ot that great 

invention: iDBtead of recording thi.Dgs and ideas tor the dissemination of 

knowleclge, we want and atrive our utmoat to prevent this aim trom being 

realized, except emng our CJVD brethren and under Certain Bpee1&l Circumstances, 

for the purpose of our mutual aecurit7, our aelt-preservation. And that •a 

1mportant. 
REF ID:A62859 e 

Writing is a COllrJl&l'&tivel.y new thing in the history of nanJc1nd. No 

complete system of writing was used before a.bout 35~9 B.C. 

Ordinary writing, the sort at writing you am I use, is perhaps an 

outgrowth or development of picture writing or rebus writing, which I'm 

sure most of you enjoyed as children. A rebus contains teaturee of both 

ordinary and C17'Fograph1c writing; you have to "decrypt" the sign1ticance 

of sane ot the symbols, combille sinale letters with syllables, prODOUDce 

the word that is represented by picturea, and so on. Here's an example 

which I have through the courtesy of tbe Bell Telephone Laboratories. Let 'e 

see how much of 1 t you can DBke out 1D halt' a minute. 

Frcm rebus writing there came in 4ue course alphabetic writing aD4 let 

me say right DOW' that the invention ot the alpbabet, which apparently 

happened only once 1n the history of mnk1nd, in aome Middl.e East Semitic 

region, 1A or near tbe Paleat1ne-Syr1a area, then spread throughout the who.le 

ot the European continent, am t1o,auy throughout most of the world, is 

perhaps mm•a greatest, most. impartut, and moat tar-reacbiDg iDveution 

because it farms the foundation ot practi~ ~our written am prin1:.ed 

knowleclge, except that in Chinese. The great achievement of the invention 

of the alphabet was. certainly not the creation of the signs or symbols. It 

involved two brilliant ideas. The first vas the id• of representing merely 

the sounds of speech by s~ols 6 that is, the idea at what we may call 

@onet1c1zat1onJ tbe second was the idea of adopting a system 1n which, 

-3-
REF ID:A62859 e 

r~ epeak1 ng, each speech sound is denoted or reprennted. by one am 

only one symbol. Simple as these two ideas seem to us llOW 1 the invention 

was e.pparently made, as I've said, only once &ll4. the inventor or inventors 

of the alphabet deserve to be rl.Dlted among the greatest benefactors ot msDkind. It made possible the recording of the JDl!m\Ory ot m&nk1nd in our 

libraries, and from that single invention have come all put and preffAt 

alphabets. Some of the sreatest of men's achievements we are nov apt to 

take tor granted; we seldom give than tm.y thought. The invention ot the art 

of writing and the invention of the alphabet are two such achievements am 

they are worth pondering upon. Where would we be without themt Note that 

among livins languages Chinese presents special i:roblems not only for the 

cryptologist but also for tbe Chinese themselves • No Sinologist lmovs all 

the 81!1, 000 or so Chinese a~la, and it 1B also tar trcm easy to mater 

merely the 91SBB or so symbols actually muployed by Cbineae scholars. How 

far mere simple it is to use only 28 to 26 s;ymbol.a ! !eillg a. D10Do&yllabic 

language, it aeel'.116 almost hopeleos to try to write Chinese by the SOl"t ot 

mechanism used iJl an alphabetic polysyllabic J.aDguap; attempts along these 

lines have been unsuccessful and the difficulties 1n memorizing a great ma.oy 

Chinese cbe.ractera acco\IDts tor the tact that even now only about l~ ot 

the Chinese people can read or write to any significant degree. The spread 

of knowledge in China is thereby much hampered. 

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REF ID:A62859 ~ 

Probably the earliest reliable 1Df'ormat1on on the use ot crypt<>sr&pby 

in connection w1 th an alphabetic language datea fr an about 900 B .c. , Plutarch 

mentioning that from the time of L)'Curgus there was in use among the 

Lacedemonsens., or anctent GreeQ, a device cal.led the sci-tale. Thia device, 

which I'll explain 1n a moment, tras definitely known to have been used 1A 

the time of Lyaaoder, which would place 1 t about 400 B .c. 'l'his is about the 

time that Aeneas 'lhct1ciw wrote his large treatise on the def'enae of fortifieatiOD, in vhich there is a cbapter devoted specifically to cryptOSl'&pq. 

In addition to mention1ng ways of physically concea.1J.Il8 messases 1 a peculiar 

sort ot cipher disk is described. Aleo a method of replacing wards a.ad letters 

by dots 1s mentioned. 

We tilld instances of ciphers in the Bible. In Jeremiah Chapter 25, 

Verse 26 occura this expression: "Ami tbe King of Shesbakh sball ch-ink 

· ... 

after tbem." Also, ~in in Jeremiah ~1:41: "How is Sheabakh taken!" 

Well, for perhaps ~ years that name "Sheehakh" remained a mystery, because 

no such place was known to geograpbera or historians. But then it was discovered that if you write the twenty-two letters of the Hebrew alphabet in 

tvo rows, eleven in one rc:M and eleven in the other, like this, you set up a 

aubstitution alphabet whereby you can replace letters by those standing 

opposite them. For example, "Shin", 1S represented by ni3eth" or vice versa, 

so that "Shesbakhn translates "Babel" 1 vbich ia tbe old name ot ''!abyl.on." 

Hebrev then did not ba.ve and still doean•t have va.rels; they must be supplied. 
REF ID:A62859 ~ 

This is an example of wbat 11 called ATHBASH "Writing, that 11 1 where Aleph, 

the first letter is replaced by Teth,, the last letter; Beth, the second letter,, 

by Shin, the next-to-the-laat, etc. By sliding the second row of letters one 

letter each time there are eleven difterent cipher alphabets available for 

use. The ol4 lf&l.mudiets went in 1br cryptography to a. considerable extent. 

Incidentally, in mentioning the Bible, I vill add that Daniel, who, after 

Joseph in Genesis, was an early interpreter of dreams and therefore one of 

the first peychoanalysta, was al.so the tirst cryptaoalyst. I say that he vae 

an early psychoanalyst, becawse you will remember that he interpreted 

Nebuchadnezzar's dreams. In the :Bible's own words, "Nebuchadnezzar dreamed 

dreams 1 wberew1 th his apir1 t was troubled, and sleep brake from hilll. " l3ut, 

unf'ortunately 1 when he woke up he just couldn •t remember tho111e troublesome 

dream&. One morning he called. for bis wise men, magicians, astrologers, an4 

Chaldean sorcerers and. asked them to interpret the 4ream he'd had during the 

preceding night. "Well, now, tell us the dream and we'll try to interpr•t 

it",, they said. To which King Nebuchadnezzar exclaimed, "The thing is gone 

from me. I don't remember it. But it•s pert of your Job to fiDd that out, 

too, an4 interpret it. And if you can•t tell me vbat the dream was, and 

interpret 1.t, things will 'happen to you. n What the king asked wae a pretty 

atUf' assignment, of course and it•s no wonder they failed to make eood, which 

irked Nebuchadnezzar no end. Kings bad a nasty habit of chopping your head 

ott 1D those days if you te.Ued. or mde a mistake, just as certain arbitrary 

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REF ID:A62859 e 

amt cruel despots are apt to do even in modern t:lme• tor mare miDOr 111fract1cu1 

such as raot following the l'artJ LiAc. So 1rl this cue it canes as DO surprise 

to lear.n that Ii~bucba4nezzar pB&sed the vord al<>ns to dea~.:rO)' !!;! the wise men 

ot Babylon, ·among "1h0Jll w; cme ot the llise men of Israe1, ntU:Ded. Daniel.. 'ffell, 

when the King's guurt\ came to fetch bim.1 Deniel begged that he be given Juat 

a bit more time. '?hen, by some act of clivination, -.. the Bible &illlp4 afq& 

that the secret was revealed to Danlel in a night v!sion--Do.n1e2 1fB.S e.ble 

to reconastruct the dream and. then to interpret it. Daniel's reputation vu 

me.de. So.me JeW:a later, Nebuchadnezzar's son :Belshazzar wao aivillg a feast, 

awl, during tbe course ot the feast, 1n the varcls ~the Bible, "ea.me forth 

fiJl8ers of a D'l.Ul'D h3Jl4 a.ad wrote over against the candleat1ck upon the 

plaster of the wall." The haD4 w.rote a secret messase. You cu imagine tbe 

apille-eh1ll1ng scene. »elsb.azzar was veey much upset, and Juat as bis 

father did., he called ror his viae men, sooths8.1C1"&1 Cbaldean sorcerers, 

maatctans au4 so OD1 but tbe;y couldn't read the message. Ap.PQ.r.'ently they 

. collldn•t even read the cipher characters1 Well, !elshazzar•s Q.ueen :rortuna.te17 rememberea wbat tbat Israelite Dau1el bad done ;vears bef'ore a.nd a!le 

suggested that Daniel 'be called 1n as a cona1.1lta.nt. Dn.u.".el ve.o e~fl .1.n 

'b7 :Belshazzar and he succeeded :1n doiaa two tbiDgs. Be succeeded not ouJ.¥ 

also he was Guccessi'ul. iD decipher .ills the meaniQS ot those strauge words 9 

' 

K1s interpretation: "U.eae" -- "God hath numbered tq Jd.Dejlom amt tinisbed 

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REF ID:A62859 ~ 

it." "Telrel" .... "'rhou are "eigbe4 1D the baltulces aD4 found wantirag." 

"Up'bars11l11 -- "Thy kiDgdam shall. be 4iv1de4 md given to the Medes and 

PersiaDs." APJ&NDtl.¥ tha chap who 414 the haadwritiDg OD the wall Jmew 

a thing or two about C1'7,Ptograpl\y, because he uaecl what we call "variants", 

or 41fferent values, far in cme caae the laat word :1D the secret wit:l»g on 

tbe wall 18 "Upba:rsin" &D4 1n the other it is "Peres") the commentators are 

a bit vague aa to why tbere are these two versiODS ot the varcl in the Bible. 

At ut rate, Ba'b)Plon was fim.abed, J\18t aa the imlcription propbesizecl,; 1t 

41.ed with :Belshazzar. 

I tbiDk thia curiCNS biblical case of the use ot crwtogra~ is 

interesting 'beca\18e I 4on rt tbiU u_v'ba4:,r baa :reaJ.q toun4 the true man1ng 

ot the aentenc• iA secret vritiag, or explained v~ the vr1t1Qg on the wall 

1a suppoae4 to give the beat ezplaaation ot the enjgnatical. sentence tbat 

bas alWIQ'll been com14ere4 one at tbe most obscure of tbe m.D7 41fticult 

acriptual. passages which have awaJceDe4 the iAterest u4 battled the ilageAuity 

oE scholars. 'tou see that th1a AVBD.t thinks tbat tba cWMt1to.rm ideog?'W 

were v.r1tten rltllout 811f 41v1s1an between the 1D41v14ual war4a, ao that the 

aeutence "voul4 be Jwat as hard to rea4 aa a. :rebus and vauJ.4 pLlZgle tbe 

most ski.Utul Clecipberer." lie goes cm to say: "The 4itt1culty woul4 have 

been •till mare increasecl it the i4eop'8mS !uui beeA grouped in aome w:wsual 

W8tJ', severing the 111.Ltural comaect1on ot tbe cOlllpOJlellt el.wnte. It the 

..a-
REF ID:A62859 e 

sigas bad been written in this IDl!Ll1ner it would have been. almost impossible 

to arrive e.t their true nea.ning." But why coul4 Daniel. read and interpret 

the writing when his competitors couldn't'l Thia our savaxlt doesn•t explain • 

.Another savant offers as his explanation of the mystery the following 

hypothea1a: Tbat the words were written in columns, as shown: 1D this slide, 

and that Daniel in solving tbe ~tery reed downwards or rather down, up, 

down. Tbil explanation 4.oesn•t aat1sfy me ~mare tban the other one. 

The a.e:ltt slide I show you 1a the acytale, which I've already mentioned 

as one of the earliest cipher deVicea history records. Tb.e acytale wae a 

wooden cylinder of specific dimensions aroUDd whicb they wrapped spirally a 

piece of parchment or leather; they then wrote the message en the parchment, 

unwound it, aa.d sent it to its desti.Qat1on by a safe courier, who baDded 

it over to tbe cmmnander far whom it was inteDAed e.114 who, having been 

provided with an 1dent1cally-climene1oned cylinder, would WiDd tbe strip of 

leather or parchment around his cylinder and thus bring together properly 

the letters representing the mesaage. This diagram nay not be accurate. I 

don't tbiJlk ~one really understan4s the acheme. The writing was done 

across the edge& of the parchment, according to aome accounts, ao4. not between 

the edges 1 as shown in this sl14e. Incidentally, you MY be interested to 

learn that tbe baton which the European fiel.4 marabal 1till carries u one 

of the insignia of hi.a h1gb office derives fran tbia very instrument. 
REF ID:A62859 ~ 

We don •t Jmov much about the use ot cryptographJ' b7 the Romana 1 but 

it is well Jmown that Caesar used an obviousl7 simple methocl.J all he did 

was to replace each letter by the one that was fourth tram it in the alphabet. For example, A would be represente4 by D, B by B, and so on. Augustus 

Caesar is said to have wsed the same sort ot thing, ODl.y even more simple: 

each letter was replaced by the one that followed it 1n the alphabet. 

Cicero was one ot the inventors ot wbat 11 now called ahartbarld. He had a 

slave by the Dame of 'l':lro, who wrote Cicero's records in what are called 

T)rronian notes. Modern sbortha.D4 is a development of Tyrq•e notation s;ystem. 

The next slide ahows same cipher alphabets ot olden times, alphabets 

used by certain historical f'igures 1ou•11 all remember. '!he first cipher 

alpbabet on the slide was emp1o)le4 'b7 Charlemagne, who lived trom 768 to 

814 A.D. The second. one vaa used 1D Engl•nc' during the reip at Alfred the 

Great, 871 to 899. '1'he third alphabet is caUed opm writing and was used 

~ancient Ireland. The alphabets below that were used much later in 

England.: the fourth one by Cbarles the First, ill 1646; tbe tuth, the 

so-called "clock cipher" 1 ~ used by the .Marquis of Worcester 1D the 17th 

Century; f1Mlly1 the last one was used 'b7 CardiDal Wola97 iD about 1524. 

In the Middle Ages cryptogr&PJ7 appears first as a method of coucealing 

proper names, usually by the simple substitution of each letter by the next 

one in the alphabet, just about as Augwstus Ca~1ar did blmdrecla of 79ars 

-li'l-
REF ID:A62859 ~ 

before. At other times the vovela were replaced by dots, without changing 

the consonanta--a method that was used throughout Europe to about 10"" A.D., 

when letters began to be replaced. by various a~, by other letters, bJ 

letters from another language, by runes which are found in abundance in 

ScamU.navia, and by arbitrary symbols. Here's an example of a runic iDBcriptiOD on a stone tbat stands before Gripsholm Castle near Stockholm, Sweden. 

The word rune means nsecret". 

Within a couple hUD4red year• tbe outlines ot modern cryptography 

began to be formed by the secret correspondence systems employed by the 

small Papal Ste.tea 1D Italy. In fact, tlle real beg1m1nga of a15temat1c, '' I 

moaern cryptology can be traced back to the days of the earq ;,years ot the 

13th Century, when the science began to be extensively emp1oyed by the 

princes aDd cbaDceriea ot the PIJpal States 1n their diplomatic relationa 

amongst themselves and with other countries 1n Europe. Tbe necessity for 

secret communjcation was tirat met by attempta 1nsp1red by or derived from 

ancient ceyptograpby, ea I've outlined ao far. There wae a special predUection for vowel aubsti tut ion but there appeared about this time one ot 

the elements which was later to play a very prominent role in all cipher 

systems, an element we nOW' call a syllaba.ry, or a repertory· These were 

lists of letters, syllables, frequently-used parts of speech and wards, with 

additions of arbitrary e~val.enta for the aamee of persons and places. 

There is still 1n existence oi:ae such syllabary aD4 liat of arb1 trary 

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REF ID:A62859 e 

I 

equivalezrta vbieh was uaed about 1236 A.D. am there &l"e other examples 

that were wsed in Veuice in 1359. 

AmoDg examples ot ciphers 1l1 medieval crJ,ptogr&:phJ' ts a collection ot 

letter& ot the Archbisbap at Napl.ea. written between 1363 anc1 13651 1a wJd.cb 

he begins merel.J w1th sJmbol subatitutiona tor the vowels and uses tbe letters 

tb&t are act~ vowel.a to serve as null& or n<>xl.-01gn1f1cant letter& to thl'ov 

not cm]J' b:f arbitrary a~ but also bf other letters. 

About 1378 an expe.rieuced cryptologist named Gabriele Iav1D4e ot Parma 

wu emplcpd aa a irotess10Dal 'b7 Clemellt VII &Del 1D tbe Vatican Library 

there 1a o collection of ciphers devised an4 used by Lavinde about 1379. It 

ccmsiats ot repertories :ln which ever7 letter is replaced by 8Zl arbitrary 

aymbo1. Sane ot these ciphers also have Aul.ls alUl a.rbitrar:r eqUivalats or 

aigDs ~or the mmes at peraODll u4 places. 'lhere 115 a court c1pbor ot Man.ta 

4&ted 139; tbat used this SJB'tem. 

At the beg.1no1fl8 of the 15th Century tbe neceae1t7 ot ba.viag variants 

- tar tbe h:lgb-trequency letters, eapeciall.y tbe VOllela 1 became obV1oua. Bere 

ia u alpbabet of tbat period which is 1ntue1t1Dg beca\llle 1t shows that even 

"-.... 

.,. .- 1D those earl.7 ~ ot crJPtolOQ' t1Jere waa al.rea47 a recognition or the 'basic 

.:,.-ea.tness ot wbat ve call e1ngle or mcm.ce.J.pbabet1c aubllt1tut1an, tl:at 1a 1 where 

every letter 1D the plain-text meusase 1s repreaeated b)r anotller arid alvap 

the sue letter. SQ1.ut10D ot tb18 tnie ot cipbel' 1 u ~ oE 'JOU -.:, 1mow 1 
REF ID:A62859 ~ 

alphabetic .laDSUase are used with great~ dit'ter1Ds frequencies. I dcm 't 

llave to go into that now beeauae ~ of 10\li at same time 01' other, have 

reacl Edgar Allan Poe's "Gold Bug", am UD!erotald the prillciplea ot tbat 

eort ot ual1818· 'l'his elide clearJ.¥ 817,avs tbat tbe eu-q Italiaa crn>togra:pbers UD4eratoocl tbe fact ot varyiDS .t.requeu.ciea 11114 1.Dtroclucecl stumbJJ.,Qg 

represented bJ' mare than a aiDgle character 1 ar b7 several characters, aa 

J'OU see 1D this al14e. I V1ll lld4 tbat tbe earliest tract tba"t tbe worlcl 

ia tbat which vas vritten iD .V..74 bJ' a Heapol1tan, whose mm vu Sicco 

SimoDetta. Be set f'arth the 'baa1c P'imliplea aa4 ~a of aul.viDg cipaers, 

aimpl.e ciphers no daabt., 'but be 4eaC%'1'bes them am their aol\ltim :la a very 

' 

clear and conc1ae farm. 

tbia al14e ia abawn what we nwq call the first complete cipher a19tem of t:tiia 

sort. '!'here are su'bst1tut1m a~ tar .-ch letter J t!ae va.rel.a have 

several equi.valent•J there are nulls; aad tJJere 1• a awn liat at arbitrary 

-- and ao on. This cipher,, dated .l4U, vu used 1n Venice, aDd 1s typical al ~ 

-13-
e REF ID:A62859 e 

'1'he step renain1ng to be taken 1D the 4eveiop.nt ot t!aeae ciphers 

waa to expaa4 the "vocabular7", tbat is, the liat ot equ1val.eAta tor tre~­

uaecl var4s, an4 a7llablea, tbe names of paraans ar.d placea, parta at 1peecb, 

aD4 ao on. Thi& step vu N&ClM!4 in Ital¥ clur1Dg tbe firat ha1t ot t!Je 

l~tb Century am becam tbe prototne ot dip.lam.tic ciphers used 1D 

pract1call7 all tbe states at Europe for several ceatur1e8. Here 11 om 

ot 78 cipbers collect.eel 1D a Vatican codex aa4 uae4 tl'am aboUt 1441 to 1"°69. 

Note tbat the equivalent& ot the plaiD-text items 1D tbia sl14e are Iat1D 

words am cmbinatiODa ot two aDl three letters, am that tbe7 are liate4 

in au m:'cler tlJat 18 aomewhat alpbabet1cal but not atric~ so. I su.ppoee 

tbat 'b)r conatant use tbe cipber clerk voul4 learn the equivalAtnta almallt b)' 

heart, so that an adherence to a strict alphabetic sequence either tar the 

plaiD .. text itema or tor their c1pber equivalents 414a•t ~their operatiou too llllCb. In this next aliAe there 1a much the same aart ot arranae-ut 1 

except that now tbe cipber equivalellta seem to be tigraphe am tbeae are 

a.t'1"aDge4 in a rather s19teatic order, t~ ease 1D encipberiDg am decipher1Jas. 

Kov we haft the real 'begfnnsnp ot what we call a oae-part cede, tlat is 1 

tbe same list will serve both tor encodiDg aQd. cleccxling. 'lbeae a19tem, aa 

I •ve aa14, rem1ne4 tbe prototnes ot tbe crntosrapJv" empl.0184 'tbroughout 

the vbole at Europe fer •~ centuries. 'lbe Pai-J. Ste.tea used them amd u late 

as 1193 ve 1'1D4 tha wae4 in Prance. l viab here to :mentim aptcU1~ tbe 

ao...ca1l.ecl King's Cemra1 Cipher uecl 1n 1572 'b7 the Spe.niah Court, am I ahov 

bere a picture ot 1t. 
REF ID:A62859 e 

JNt there were tvo excepttoaal cuea which ab.ow tbat the r1gi4it7 ot 

we have been talking about in thia 'brief h1.atar1cal. •Ul'Y81 • scme of the 

, Louis XIII aa4 XIV exemplifJ tbeae except;iou. ln tile cue ot tmae Prach 

Court c1pbara ve tltd tbat a P.rench cry,ptolog1at DIUlllld ADtcmio Rosa1gnol.1 

who was emplo)'84 bf Car41Dal RicheUeu, umteratood quite veU the vealmessea 

ot tbe cme-pU't codes am •1llalm-:l.ea. It waa he wbo, :ln about u;a.e, 1.Dtroa7lla'baey, 1n wb1cb fer euco41Dg a message the items iD the vocabul.&17 &1'8 

listed 1n some a19teDatic orcler, D881"~ a.bnQa alpba'betieal.J the ccile eqW.va• 

far ease 1rl deco41DS1 1D vhicb tbe cocle equivalents are 1:1.atecl 1A a19teml:t1c 

) 

m'4er, numar1~ ar alpba'beti~ as tlle cue~ 'be, aDl1 alonp14e each 

tbe 3$1 COl'ftapmdence ot 1.touia X1Y IJaal abO\lt 611 tt.na, with cc4e groupa 

ot two a.rd t!:lree digits. Bot &t &11 bad, for thoee 4qa I 

Bov tb1• lm"t ~ s;vatemt voul4 ~ to be quite •eCUl"e, &D4 I suppoae 

11; vu 1n4ee4 ao, tor those -.r~ 4ap. ot crnto£raph1c Aevelopne:ut--but 1t 
REF ID:A62859 ~ 

vun •t proof aptnat the clevermaa at British braimJ, tor the emtaeDt 

' 

mtheat1c:l.an John Wallis solved me1sagea in it 1D 1689. levw \IDller .. 

perm.pa ita lowe1t level ull4e1" lapoleon the Oreat. lt ia a tact that 1D 

Iiapoleon •a Bw111&D enteZ'priae the whole or bis &l'JIW uae4 by a aiDgle 

code book ot ~ 21f groupa, peacticalq v1tbout variallta# e'V'eD for the 

'i 

effect 117 Cr.ar Al.exan&Ser I h1maelt. Ve WOil •t be t&l" wroag 1D believiDg that 

azd lmocked tbem C>U't ot Warl4 War I. 

1'he otber l6tb Centuq BLJ&I, cipbers tbat cout1tute4 t!le seco.a4 excepq.W.t.e 41.tterent fi'cm those I've abalm JCN• In thie exception tbe cipbera 

were mncal.pbabetic, but aom letter• 1*1 the same equi'ValeDt, ao that cm 

clec1pberment the context ba4 to be ue4 to 4ec14e vbich at two ar more 

-16-
e REF ID:A62859 e 

PQ$&1ble pl.a1n ... text values vu the one -.nt b)" each cipher letter. lel"e'a 

a oll4e wh1cJi shows m.te auch cipher used by the Maltese Inquisitor in 1585. 

tou.•11 note tbe.t tbe 41g1t 8 baa two values, A aD.11 'l; the 41g1t 2 baa three 

values, U, V, and. B, and ao an., '!here were two digit• uaed as nulls 1 1 au4 8J 

digits with dota above them atoocl for vorda such ae Qua, Que, Qul,. aD4 so oa. 

Bere•s a el14e which ahawa ba.r a me1aase woul.4 be e11cipbere4, an4 alao 

&lp:r Allan Poe describea & cipher of this same geD8l'&l tJP8, wbere the 

decipherer must choose between tvo 01' more possible plaill-text equ1valeDta 

in buil4blg up bia pla.11>. text .. the latter su141Jas the choice ot the right 

equivalent. Tbe trouble vith this sort ot cipher ia tllat 1011 bave to have 

pretty am.rt cipher clerks to operate it amt eveu thea I 1zrm,g1ne th$t ill llBQ1' 

places there voul4 be clou'bttul. 4ec1phermAt& of var4s. It wasn't real.J.1' a 

pl"&et1cal system even in tbole 4ap 'but it cou14, if uaed ski~ aD4 with 

onJ-7 a ..U UJQQDt; o£ text, give a ~t plenty ot headaches. But 

aucb iiJ&tema 4f.cln •t last '1f!lr1 lOD& because ot the practical. 41tt1cult1ea in 

us!Dg them. 

'l'he first replar or off'1.c1al cipher bureau 1D tbe Vat1ca1\ vu .. tablisbed 

1n about 1'4• 1 aa4 in Vellice at about tlle __. time, about one hwdred ~· 

before a replar cipber bureau vu eatab11ahe4 m Prance b1 Car4Sllal Richelieu. 

It 111 :lntereati.Dg to o'bBe:w that u.o DllV or reDILl"kable ideu ror crntoaysteu 

were developed f~ a couple ot JND4re4 JW'• after the camplex Ollel l •ve 

-17-
REF ID:A62859 e 

described as having been developed bf the various Pape.l cryptologists. One· 

part a.DO two-pa.rt syllabariea am simple or complex oDes w1 th veriaDts were 

in use for JllBDY' cleca4es / but later on, :tn a few caaea 1 the code eqμivalenta 

were superenciphered, that is, the co4e gi-oups formed the text t~ tbe 

application of a cipher, generally by rather s1mpl.e systems of a441t1vea • 

Governmental codes were of the two-part type and were superenciphere4 by the 

more sophisticated countries. 

The first l>ook or extenai ve treat1ae on crwtogra1>h7 is that by a Qermn. 

abbot Damed 'l'rithemiu.s, who published in 1531 the first volume of a P1 azme4 

4.-volume monumental work. I said that he planned to publish four volumes; 

but he gave up a.tter tbe third one, because be wrote so obacureq a.ml made 

such fantastic claims tbat he waa charged with being ill league with the Devil, 

which was a rather dangerous aeeoc1at1on in those or evea in these days. The7 

didn •t burll 'rrithemius but the7 did burn bis boolsiJ. Thia may be a good place 

to present a slide which shows that the necessity for secrecy in thia bws1Deae 

was recopized from the very earliest 4aJa of cryptolomr, and cert&1rll1 b)' 

'lrithemius.·,, Bers ';ts the sort of oath that '.L'l'ithemius recommended be admn1•tere4 

to students in the sc1«mce ot cryptology. All ot you ba.ve eubacribe4 to a 

somewhat a1m1Jar oath, but we now go further and. back up tbe oath with a rather 

strict law. You.•ve all rea4 tt, I'm sure. 

We come now to some examples from more recent biator;y. This sl14e shows 

a cipher alpha.bet uaed by Mary, Queen of Scots 1 who reigned from 1542 to 1567 
-. 

REF ID:A62859 e 

her. 

'!he Spmi•h Court \Ul4er Ph1U1p II, 1n tbe JeU'I 1555-1596, use4 a gnat 

18Q1 cS.phera an4 here'• one ot them. You see that it 11 quite cQmplex tor 

those -.i-]¥ 4&111 azd :tet ciphers or tld.e acrt were aolve4 w u endmnt 

French matheatician mmed Vi.eta, the father ot lllDderD algebra. Jn 1569 

he became a Cwelor ot i:.ruement at 'lam-a u4 tl:len friY)" Couueiar. 

Wbile 1D tba.t 3ob 'be solved a. S1JM1sh cipher &JBtem uaillg JllOff than 51" 

cba.1'8.ctera, ao tbat all the S;imdsb 4taiatchea taJHag into French baa4a 

were eaa~ read. l'hill1p vas so eOAY1nced at tbe 11ecurit7 or his ciphers 

tbat when tbe :f'OUD4 the French were aware of tJle cOllteDta of bia cipher 

41apatcbea to tbe Netberlazda, be compla1Md to the PoJ!e. t!lat tbe Prezich 

were utnc acrcery a9du.t b1m. Viet& vu ca:nea m the Cal"pet am1 forcecl 

to explain how be •cl aolvecl the cipbers 1A order to avoicl 'beizlg clm'ged with 

'J9ie mxt crntalogiat I vut 10'1 to !mow eaaething about 1a u.othar 

Italian •a'VBllt vho wrote a book, published 1D 15631 1A vb1ch be sboved 

certa1D tniee at cipher alpbabeta that bave COJl8 4~ in biatoq aa4 are 

temu u Porta•• Al.pb&beta. Here •a au exam,ple ot the Porta ~'bl.et ahovirC 

one &lpb&'bet with key letters A or B, auotber al.pba'bet with key letters C 

.. 19. 
REF ID:A62859 tt 

or D, and ao on. I don't want to go uto exactly how the ke7 letters are 

wsed; it is sufficient to say that even to this day cryptograms usizlg the 

Porta a.lphabets are occas1ona111 encol.Ultere4. 

TIBt Pai:'ta 1s table was actually used in. official correepandence 18 

sham by this slide 1 which is a picture of a table fow:d among the state 

papers of Queen El.izab&tb•s time; it was used for cCBDmUDicating ldth the 

B.Qglish .Ambassador to Spain. Porta was, in rq op1J).1on1 the greatest at 

the ol4 writers on ceyptolOQ. I alao think he vas one at the earl7 but 

bJ no means the :f':lrst crn>tamJ.yat able to eolve a a19tem ot keyed aubst1 ... 

tution, that 111 where the ltq is changing consistentl)" as the message 

imdergoes eneipberment. IQciden~, Parta also was the inventor at the 

photographic camera, the progenitor at which was kaown as the camera obacura. 

The next slide shows a picture of What c?'7,Ptograpbers usuall.7 call the 

Vigenere Square, the Vigenere Table1 ~ the Vigenere Ta'bleau. It conaists 

of a set of twenty-six alpbabete successively d1apl.ace4 one letter per :raw 1 

with "the plaiD-text letters at the top of the square, the ke7-letters at 

the sic1e 1 aid the cipher lettere 1u14e. The method of using tbe table is 

to agre-.s upon a key word, which causes tbe equivalents of the pla1n. ... text 

letters to change as the J;ey changes. Vigenere is coD1110nly cred.ited w1th 

ba.Ving invented that square and cipher but he reaJ.11 dicln•t ana, what'& more, 

never said be 414. Here's a picture of his table as it appears 1D bi• book, 

the f'irst edition ot which was published in 1586. It is more complicated 

than a.a described 1n orc1~7 bootl on cr:r.ptology. 

-as-
REF ID:A62859 e 

Bere is one mare e-xam;pl• ot another ol4 official. cipher. Here ce tbe 

alpha.beta cm a card vbich coulcl be slid up &Dd dovn, a.a a ma.ua of chaagiag 

the key. Jlere is auother,. call.eel the "two-aqua.re t::S.})lm"", or "tvo-alpl:aa.bet 

cipher". It is a tacsimUe of a State Cipher ueed 1n Charles the Firat•s 

time, 1D J..6271 for caumuuicating with ha.nee am !'laudera. It involves 

coordinate• aid I want rou to notice tbat there are two caa:plete al.;pba.beta 

inside it, iD~ed to omootla out t.recpmciea. ~ letters ot the lteyworda 

OPnMUS u4 DOMtltJS serve as the coordinates used to represent the lettera 

inside tbe sciuore. Bere •a :pa:"t of a. cip!Jer uaed 'b7 GeOl'p 1U date tile lat 

of September 1799. 

One writer cleaei.•ving spec:lGl. attention as a kaowleclpable crn>toJ.oiiat 

1n tbe 17th Century, and the one with vhoae cipher 1'11 clo&e this J.ectlll"e, 

1• Sir FrBDCia kcon, who iDVented a very useful cipher au4 111mt10Ded it 

tar tbe t1rst t1me in b18 .A4vancement ot Lem.:niy, piblisbecl in l6fJ~, lA LomlOA. 

i'he deticription ia so briet tlat I doubt v:bother IUaDI' persona wxlerstoad what be 

w-.. 4r1Vin8 at.. But Be.con deecribecl it 14 full detail, with ex;am.ples, iza. 

his ~eat book De Au£aentia Scient1arum, vb1cll wa publia1*1 al.moat 2S ,_,... 

la.ter, iZl J.623, aad .which t:lrat appeared in u IDsU•h tnnalatiou 'b7 Gilbert 

Wata in l.6Jt.e UDder the t:l.tle '!hf. Ad'VUCemcnt of Lee.miss• JllM:on called hiu 

invention the lliliteral Ci)?her alld it 1a ao Sngeni oua that 1 think you allould 

be tal.4 abou.t it so that 10\1. will all ~ umlerstaad .it. 

:en h1a De Argspwgt1s :Bacon writee 'briefly about cipbera in gemral amt 

-21-
REF ID:A6285~ 

says that the virtues requh'ed 1n them. are threes "that they be easy aDd 

not laborious to write; tha.t they be sate,. a.n4 impossible to be deciphered 

without the key; and lastly, that they be, 1f poa1ible, euch as not to 

raise suspicion or to elude inquiry." Re then goes on to say: "But for 

avoiding suspicion altogether / I Will add another contrivance, which I 

devised myself vben I li.'8.8 at Par18 in m:f early youth, and which I still 

think worthy of preservation." Mind you, this was 4S ~a.rs later! Let's 

consult Bacon 'far turther details. Bere is a slide showiug a couple ar 

pages ot the Gilbert Wats' traI1$lat1on or :&.con's De Aupentis Scient1arum. 

Bacon shows vhat be calla "An Example or a Zi-literarie Alphabet", that ia, 

one compoaed at two elements, wh1cb1 taken in groupings ot tivesiJ ;yields 

32 permu.tations. You can use these permutations to represent the letters 

ot the alphabet, Sa)'& l3aco11, but you need ODl.y 24 at them1 becs.uae I am J 1 

U and V, were then used interchangeably. 'l'hese permutations at tvo different 

th1np--tbey my be "a's" ~ "b•s", "l's" and "2's", pluses aiid minuses, 

app1ea and oranges, anything you plea.ae-.. ce.n be used to express or signify 

messages. Bacon was, 1D f'act / the inventor of the b1.Da.17 code which farms 

the bae1a or modern electronic digital computers. Bacon s1ve.o a. brief 

example in the vord 'TUGE" --the Latin equivalent tor our modern "SCRAM". 

Jlere it is, • you see. Here's another example, which quite obviously isn't 

what it appears to be--a crude picture of a caat1e1 in wbich there are shaded 

aD4 unshaded stones. It was drmm by a. friend who was a physician 8Jld. the 

.. 22-
REF ID:A6285~ 

message conveyed by it ia: 

M;y bws1De1s is to write pl"eacriptiODB 

Ard then to eee mt dosee talrenJ 

But ~ i: fill4 I apend UV' t.1-

Endeavoring to out .. :Bac.cn Bacon. 

AD4 here'• another ezample, not quite 10 obvious. 'nle meseage cOD.v«eyed 1a1 

So far &11 this ia simple en.ougb--to much so, :a..con S"'81 for the 

example he used in the cue ot the worcl l'OOE ia patent4' crnttc aa4 v<Nl.4 

not avoid. •uap1c1on umer exam1nat1on. So Bacon goes an to describe tbe Dat 

step,, vbich 18 to have at bani a "Bi-formed Alphabet" 1 that is 1 one 1D which 

all the letter• or the alphabet, both capit.al aDd small, are represented 'bJ' 

tvo •liahtl.7 41.tterent f'aru ot letters. Having these two different forms 

at baD4, when you vat to encipher your secret mea•ace you write another 

exteraal an4 innocuoua me•sase five times aa long aa 10Ul" secret me11age,, usiag 

the appropriate two f'arms ot letters to correspond to the "a's" an4 ''b•s" 

repreaent1Dg you:r aecret me11ap. Here•e lUGI, encipbered vithb an exterDal 

message saying "Manere te volo 4enec venero", mea111ng "Stay where you are 

'Ull'til I come." In other vord.1, vbereaa the real message sa;va "SCRAM", the 

phoney one •&JS ••stick arouu4 _.vhil~J wait for me." !a.con gives a much 

longer example, the SPAR'tAB DlSPA'MB; !Jere it is, aQ4 here'• the secret •••ase 

which 1t conta1m. 

Ba.con'• b111teral c1pber ia an extremely ingellious contrivance. Tbere 

can be no queat1on whatsoever about its autbent1c1ty and utility u a vali4 

-23 ... 
REF ID:A62BS/I 

Jlere '• a ma4erA example vh1ch '!,Wea two sl~tly 41ff'erent fem.ta ot type 

...... =z.;o Q ~·~ .j. 

'l'l&e .i:act tbat :Baecm inve4ted this ci~ IUll2. described 1t 1n such 

iu those :pl.qa by using his e1pher. tt you'd like to learn mare about tbis 

tbeorf I sugeat vita aCD! cl1...-0f1dence that you re&\ a book entitled ~ 

awl I Wl"Ote thEr book which ~- publlsbed 1.:i late 1957 by tho Cambridge 

ID tu uat lecture wetll take up cr;n>tology aa used during the period 

of the Juumoicau RevoJ.ution 'b7 both tbe Colcmie.l am. the !r1t1sb Forces in 

America. 

I 

I