
Baconian Cipher
To encode a message, each letter of the plaintext is replaced by a group of five of the letters 'A' or 'B'. This replacement is done according to the alphabet of the Baconian cipher, shown below. a AAAAA g AABBA m ABABB s BAAAB y BABBA b AAAAB h AABBB n ABBAA t BAABA z BABBB c AAABA i ABAAA o ABBAB u BAABB d AAABB j BBBAA p ABBBA v BBBAB e AABAA k ABAAB q ABBBB w BABAA f AABAB l ABABA r BAAAA x BABAB
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Affine Cipher
In the affine cipher the letters of an alphabet of size m are first mapped to the integers in the range 0..m  1. It then uses modular arithmetic to transform the integer that each plaintext letter corresponds to into another integer that correspond to a ciphertext letter. The encryption function for a single letter is where modulus m is the size of the alphabet and a and b are the key of the cipher. The value a must be chosen such that a and m are coprime. Considering the specific case of encrypting messages in English (i.e. m = 26), there are a total of 286 nontrivial affine ciphers, not counting the 26 trivial Caesar ciphers. This number comes from the fact there are 12 numbers that are coprime with 26 that are less than 26 (these are the possible values of a). Each value of a can have 26 different addition shifts (the b value) ; therefore, there are 12*26 or 312 possible keys. Plaintext: vogen wphfo mrtno ctfvo svrdo ixdlo yzpto ednjo ufzro
khlzo ajxho qljpo gnvxo xqigp nsuop dugwp twsep
jyemp zaqup feokp vgasp limap bkyip rmkqp howyp
yrjhq otvpq evhxq uxtfq kzfnq abrvq gfplq whbtq
mjnbq clzjq snlrq ipxzq zskir puwqr fwiyr vyugr
lagor bcswr hgqmr xicur nkocr dmakr tomsr jqyar
atljs qvxrs gxjzs wzvhs mbhps cdtxs ihrns yjdvs
olpds enbls upnts krzbs bumkt rwyst hykat xawit
nciqt deuyt jisot zkewt pmqet focmt vqout lsact
cvnlu sxztu izlbu ybxju odjru efvzu kjtpu alfxu
qnrfu gpdnu wrpvu mtbdu dwomv tyauv jamcv zcykv
peksv fgwav lkuqv bmgyv rosgv hqeov xsqwv nucev
expnw uzbvw kbndw adzlw qfltw ghxbw mlvrw cnhzw
spthw irfpw ytrxw ovdfw fyqox vacwx lcoex beamx
rgmux hiycx nmwsx doiax tquix jsgqx zusyx pwegx
gzrpy wbdxy mdpfy cfbny shnvy ijzdy onxty epjby
urvjy kthry avtzy qxfhy hasqz xceyz neqgz dgcoz
tiowz jkaez poyuz fqkcz vswkz luisz bwuaz rygiz
ibtra ydfza ofrha ehdpa ujpxa klbfa qpzva grlda
wtxla mvjta cxvba szhja jcusb zegab pgsib fieqb
vkqyb lmcgb rqawb hsmeb xuymb nwkub dywcb taikb
kdvtc afhbc qhtjc gjfrc wlrzc mndhc srbxc itnfc
yvznc oxlvc ezxdc ubjlc lewud bgicd riukd hkgsd
xmsad noeid tscyd juogd zwaod pymwd fayed vckmd
mfxve chjde sjvle ilhte yntbe opfje utdze kvphe
axbpe qznxe gbzfe wdlne ngywf dikef tkwmf jmiuf
zoucf pqgkf vueaf lwqif bycqf raoyf hcagf xemof
ohzxg ejlfg ulxng knjvg apvdg qrhlg wvfbg mxrjg
czdrg sbpzg idbhg yfnpg piayh fkmgh vmyoh lokwh
bqweh rsimh xwgch nyskh daesh tcqah jecih zgoqh
qjbzi glnhi wnzpi mplxi crxfi stjni yxhdi oztli
ebfti udrbi kfdji ahpri rkcaj hmoij xoaqj nqmyj
dsygj tukoj zyiej paumj fcguj vescj lgekj biqsj
sldbk inpjk ypbrk ornzk etzhk uvlpk azjfk qbvnk
gdhvk wftdk mhflk cjrtk tmecl joqkl zqcsl psoal
fuail vwmql bakgl rcwol heiwl xguel nigml dksul
unfdm kprlm ardtm qtpbm gvbjm wxnrm cblhm sdxpm
ifjxm yhvfm ojhnm eltvm vogen lqsmn bseun ruqcn
hwckn xyosn dcmin teyqn jgkyn ziwgn pkion fmuwn
The decryption function is where a  1 is the modular multiplicative inverse of a modulo m. I.e., it satisfies the equation The multiplicative inverse of a only exists if a and m are coprime. Hence without the restriction on a decryption might not be possible. It can be shown as follows that decryption function is the inverse of the encryption function, Read more ... 
ROT13 Cipher
Applying ROT13 to a piece of text merely requires examining its alphabetic characters and replacing each one by the letter 13 places further along in the alphabet, wrapping back to the beginning if necessary. A becomes N, B becomes O, and so on up to M, which becomes Z, then the sequence continues at the beginning of the alphabet: N becomes A, O becomes B, and so on to Z, which becomes M. Only those letters which occur in the English alphabet are affected; numbers, symbols, whitespace, and all other characters are left unchanged. Because there are 26 letters in the English alphabet and 26 = 2 * 13, the ROT13 function is its own inverse: ROT13(ROT13(x)) = x for any basic Latinalphabet text x An example plaintext to ciphertext using ROT13:
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Polybius Square
A Polybius Square is a table that allows someone to translate letters into numbers. To give a small level of encryption, this table can be randomized and shared with the recipient. In order to fit the 26 letters of the alphabet into the 25 spots created by the table, the letters i and j are usually combined.
Basic Form:
Extended Methods: Method #1 Plaintext: vogen
Method #2 Bifid cipher The message is converted to its coordinates in the usual manner, but they are written vertically beneath: v o g e n 1 4 2 5 3 5 3 2 1 3They are then read out in rows: 1425353213 Then divided up into pairs again, and the pairs turned back into letters using the square:
Read more ... Method #3 Plaintext: vogen
Read more ...[RUS] , [EN] 
Permutation Cipher
In classical cryptography, a permutation cipher is a transposition cipher in which the key is a permutation. To apply a cipher, a random permutation of size E is generated (the larger the value of E the more secure the cipher). The plaintext is then broken into segments of size E and the letters within that segment are permuted according to this key. In theory, any transposition cipher can be viewed as a permutation cipher where E is equal to the length of the plaintext; this is too cumbersome a generalisation to use in actual practice, however. The idea behind a permutation cipher is to keep the plaintext characters unchanged, butalter their positions by rearrangement using a permutation This cipher is defined as: Let m be a positive integer, and K consist of all permutations of {1,...,m} For a key (permutation) , define: The encryption function The decryption function A small example, assuming m = 6, and the key is the permutation : The first row is the value of i, and the second row is the corresponding value of (i) The inverse permutation, is constructed by interchanging the two rows, andrearranging the columns so that the first row is in increasing order, Therefore, is: Total variation formula: e = 2,718281828 , n  plaintext length Plaintext: vogen vogen
vogne
voegn
voeng
voneg
vonge
vgoen
vgone
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vgneo
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vegon
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