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| Extended Baconian Cipher | |
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| Tweet Topic Started: Mar 7 2014, 07:03 PM (247 Views) | |
| novice | Mar 7 2014, 07:03 PM Post #1 |
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Super member
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The Baconian cipher is 400 years old and a brief cipher text can be quite difficult to solve because of homophones. The idea is to make a key by assigning either an 'A' or a 'B' to each letter of the alphabet. Then to spell out the message using five characters per plaintext letter -- 'AAAAA' for plain 'a', 'AAAAB' for 'b' and so on, combining 'i' and 'j' and also 'u' and 'v'. So if the key were: abcdefghijklmnopqrstuvwxyz ABBAAABAABBBBBABABABAABBBA Then plain 'a' could be represented by UOIAD or ZFVEA ... The extended Baconian enciphers all 26 letters from AAAAA for 'a' to BBAAB for 'z' and is a binary cipher. Considering the starting era, that's quite nice. |
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| mok-kong shen | Mar 9 2014, 02:06 PM Post #2 |
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NSA worthy
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Two remarks: (1) Bacon's bilateral cipher, according to H. F. Gaines, Cryptanalysis, pp. 6-7, is originally disigned as a concealment cipher, employing approriate corresponding steganographic means to transmit the encoded stuffs, i.e. his encoding of e.g. "D" as "aaabb" does not mean the actual trasmission of these "a"s and "b"s in the normal/standard font of the communication under consideration. If there were more than 2 alternatives, i.e. e.g. all lower-case characters are employed rather than merely "a" and "b" in the present context, a similar steganographical processing, though intuitively superior, would be too complicated to be practically feasible IMHO. (Thus the word "Extended" in the title of the thread seems to be questionable.) (2) Bacon's encoding employs two symbols "a" and "b". This is evidently equivalent to "0" and "1". His code for "D" above can hence just as well be expressed as "00011", i.e. a 5-bit encoding in modern terms. This fact is IMHO remarkable in view of the fact that the binary system is commonly attributed to G. W. Leibniz, who however lived later than Bacon (Bacon 1561-1626, Leibniz 1646-1716). Edited by mok-kong shen, Mar 9 2014, 06:14 PM.
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7:28 PM Jul 11