Feynman Ciphers

According to a 1987 post by Chris Cole (who was then working at Peregrine Systems) to sci.crypt on Usenet, the following three short ciphers were passed to Richard Feynman by an unnamed fellow scientist at Los Alamos (hence “The Feynman Ciphers”). The first was cracked by Jack C. Morrison of JPL, but the other two remain unbroken.

Feynman Challenge Cipher #1 (Solved!)

MEOTAIHSIBRTEWDGLGKNLANEAINOEEPEYST
NPEUOOEHRONLTIROSDHEOTNPHGAAETOHSZO
TTENTKEPADLYPHEODOWCFORRRNLCUEEEEOP
GMRLHNNDFTOENEALKEHHEATTHNMESCNSHIR
AETDAHLHEMTETRFSWEDOEOENEGFHETAEDGH
RLNNGOAAEOCMTURRSLTDIDOREHNHEHNAYVT
IERHEENECTRNVIOUOEHOTRNWSAYIFSNSHOE
MRTRREUAUUHOHOOHCDCHTEEISEVRLSKLIHI
IAPCHRHSIHPSNWTOIISISHHNWEMTIEYAFEL
NRENLEERYIPHBEROTEVPHNTYATIERTIHEEA
WTWVHTASETHHSDNGEIEAYNHHHNNHTW
(380 characters, 5 x 76 transposition cipher, start from the last position and step back 5 each time, then repeat starting from the letter one before the last position etc) --> Chaucer, Canterbury Tales:-
WHANTHATAPRILLEWITHHISSHOURESSOOTET
HEDROGHTEOFMARCHHATHPERCEDTOTHEROOT
EANDBATHEDEVERYVEYNEINSWICHLICOUROF
WHICHVERTUENGENDREDISTHEFLOURWHANZE
PHIRUSEEKWITHHISSWEETEBREFTHINSPIRE
DHATHINEVERYHOLTANDHEETHTHETENDRECR
OPPESANDTHEYONGESONNEHATHINTHERAMHI
SHALVECOURSYRONNEANDSMALEFOWELESMAK
ENMELODYETHATSLEPENALTHENYGHTWITHOP
ENYESOPRIKETHHEMNATUREINHIRCORAGEST
HANNELONGENFOLKTOGOONONPILGRIM

Feynman Challenge Cipher #2

XUKEXWSLZJUAXUNKIGWFSOZRAWURORKXAOS
LHROBXBTKCMUWDVPTFBLMKEFVWMUXTVTWUI
DDJVZKBRMCWOIWYDXMLUFPVSHAGSVWUFWOR
CWUIDUJCNVTTBERTUNOJUZHVTWKORSVRZSV
VFSQXOCMUWPYTRLGBMCYPOJCLRIYTVFCCMU
WUFPOXCNMCIWMSKPXEDLYIQKDJWIWCJUMVR
CJUMVRKXWURKPSEEIWZVXULEIOETOOFWKBI
UXPXUGOWLFPWUSCH

Feynman Challenge Cipher #3

WURVFXGJYTHEIZXSQXOBGSVRUDOOJXATBKT
ARVIXPYTMYABMVUFXPXKUJVPLSDVTGNGOSI
GLWURPKFCVGELLRNNGLPYTFVTPXAJOSCWRO
DORWNWSICLFKEMOTGJYCRRAOJVNTODVMNSQ
IVICRBICRUDCSKXYPDMDROJUZICRVFWXIFP
XIVVIEPYTDOIAVRBOOXWRAKPSZXTZKVROSW
CRCFVEESOLWKTOBXAUXVB

Note: I found these ciphertexts on John’s Javascript Secret-Code Systems page.

6 thoughts on “Feynman Ciphers

  1. Anne-Lise Pasch on January 25, 2013 at 12:09 pm said:

    The first Feynman is a modulo 384 transposition cipher? I’m pretty certain it’s a 5×76 Horizontal / Vertical route transposition cipher. Can it be both?

  2. Anne-Lise: as far as I know, they’re both semi-mathematical ways of describing the same thing. Which is “start at the end letter, and step backward 5 characters at a time (one pass at a time) to reveal the hidden message“. 🙂

  3. Anne-Lise Pasch on January 25, 2013 at 10:38 pm said:

    *g* Right then. I need to learn more math! :>

  4. http://www.austininc.com/SciRealm/CodeSystems.html

    Hi, just letting you know that the link to my site changed – AOL dropped hosting awhile back

  5. Anne-Lise: revisiting this page, I think your description is a bit more accurate (the maths is sort of correct, but not particularly helpful), and that Feynman Cipher #1 would indeed be better described as a 5×76 transposition cipher. Text updated accordingly, thanks! 🙂

  6. Pingback: A quick look at the Feynman Ciphers... -Cipher Mysteries

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