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What encryption is this?

  1. Mar 8, 2010 #1

    I'm sure this will be completely obvious for someone, but it eludes me.
    What type of encryption is used in the following text? (this isn't homework)

    Code (Text):
    Ysq xaxrvl! W zsix yfi dmdxd kvaw obdvcl! A'q oxrp jwvr loifq xatt pcm wixnk mgyk mids uvtvkzby xabs, sil xabs yok rhmhzby xh wo nwll tgy ldusfbnx Jspox picvyvms. Zh'k nnlt fz'Xvxwdzs Osgz bvwfk t mokod ntvkrgkl

    Xbfe zg ksfxtywfk rhu nwdp gxvvf yim uaty, ks ahpvtmper yfi zew t lriyl hk tncl

    Tym aep rmhx, bf pcm'vx mhv tavlm tf qjevd tywk, wxgd ds s ChnTlpw qxlsruw abmh kvw takajs: "Xvxwdzs qsn trv o bikd aer A atgt dm lmfx brqo" eqw I'cz zshd yfi mt pbty ggqxmhzby. Em lods hsbgt.

    Sm llx pap, Gsq'l poiyarz hn fij rxqt gfgnxvt kvwvx hn ywk ghfplhwv, bgsgwjiw uy Rqlmobszcf'w kxcvbl evmimwlc. Dxeg of irx olh!

    Kmgveisdc, Ykeurai, Ukaergr, tgd Dolxaxw, kvw ghhlvgl hnwej cf xax iehwvgxt
    Not any ROT-n type algorithm, I know that. Any help would be appreciated because this is driving me crazy.
  2. jcsd
  3. Mar 8, 2010 #2


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    Homework Helper

    There is no way of knowing - that's rather the point of encryption!

    but given that it is broken up into words and assuming you got this from your little sister's diary rather than a bunker under the pentagon it's probably a simple substitution cipher.
    So individual letters are swapped for other letters, if you know the most common letter in your language and the most common short words and pairs of letters it's very easy to crack
  4. Mar 8, 2010 #3
    I doubt it, notice that there are several letters that are on their own, namely w, t and s.
    In English, the only letters that do this are A and I.
  5. Mar 8, 2010 #4
    Hmm, "ggqxmhzby".

    Got an enigma machine handy?
  6. Mar 8, 2010 #5


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    Staff: Mentor

    Then just go one step farther. The substitution key changes based on somehing, like the character count or line count, etc.

    What is the source of the text?
  7. Mar 8, 2010 #6


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    Science Advisor
    Homework Helper

    Looks polyalphabetic. Vignere cipher, I imagine.
  8. Mar 8, 2010 #7


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    Gold Member


    This link may help: http://www.vbforums.com/showthread.php?t=345183"

    I would guess this is a rotating cypher because no phrase is repeated in the message, the VB code at the bottom may help crack it. Be patient and I am sure you will find it soon, make sure you include "special characters in the rotation", they are sprinkled in the text.

    Text from the VB forum, from the link above;

    Rot13 simple means rotating alphabet by 13 characters. It is a very primitive encryption method which can be easily decrypted on knowledge. But for a non-technical user it still remains an unsolved mystery. Rot13 encryption is very easy to understand and use. It is very similar to the Caesar-Encryption method. Here what we do is rotate the character backwards or front by 13 characters in the ASCII table. The means "a" becomes "n" and "p" becomes "}". This method has been used in many news delivery systems as to prevent third parties from gaining easy access to it in the past. But now there are many better encryption systems being used which remain hard to be decrypted. Rot13 uses very simple algorithms and the encryption/decryption functions can be easily made.

    What is Rot-N encryption?
    Rot13 and Rot-N are very similar with the only exception that Rot-N encryption rotates each character by any number of digit rather than 13. It is basically a number between 1 to 25 so it remains within the ASCII table.

    Here is a simple visual basic function for encrypting/decrypting a string:-
    Rot-13 was basically made only for typed characters and not any extra signs or special characters so trying characters like "?ot; would cause the program to fail. Anyways you can modify the function to fit all special characters too.

    Good luck...


    P.S. If you want a real good cryptography book, check out this one https://www.physicsforums.com/showthread.php?t=341950".
    Last edited by a moderator: Apr 24, 2017
  9. Mar 8, 2010 #8


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    Gold Member

    It is a vignere cipher. The key has something to do with egypt =)
  10. Mar 9, 2010 #9
    Crazy, I found an online tool and it cracks it :D (well, partly, I'm messing up the first half, but the information doesnt seem that interesting anyway)
    Thx Freddie
    Last edited: Mar 9, 2010
  11. Jan 8, 2011 #10

    Actually, "Yfi" repeats itself a couple times if you look at the first few sentences. This Encryption is from freddiew's video about the portal gun on youtube
    Last edited by a moderator: Apr 25, 2017
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