easy ciphers

Easy Ciphers Tools:
cryptography lectures
popular ciphers:



















Caesar cipher

Caesar cipher, is one of the simplest and most widely known encryption techniques. The transformation can be represented by aligning two alphabets, the cipher alphabet is the plain alphabet rotated left or right by some number of positions.

When encrypting, a person looks up each letter of the message in the 'plain' line and writes down the corresponding letter in the 'cipher' line. Deciphering is done in reverse.
The encryption can also be represented using modular arithmetic by first transforming the letters into numbers, according to the scheme, A = 0, B = 1,..., Z = 25. Encryption of a letter x by a shift n can be described mathematically as

Plaintext: unfirm
cipher variations:
vogjsn wphkto xqilup yrjmvq zsknwr
atloxs bumpyt cvnqzu dworav expsbw
fyqtcx gzrudy hasvez ibtwfa jcuxgb
kdvyhc lewzid mfxaje ngybkf ohzclg
piadmh qjbeni rkcfoj sldgpk tmehql

Decryption is performed similarly,

(There are different definitions for the modulo operation. In the above, the result is in the range 0...25. I.e., if x+n or x-n are not in the range 0...25, we have to subtract or add 26.)
Read more ...
Atbash Cipher

Atbash is an ancient encryption system created in the Middle East. It was originally used in the Hebrew language.
The Atbash cipher is a simple substitution cipher that relies on transposing all the letters in the alphabet such that the resulting alphabet is backwards.
The first letter is replaced with the last letter, the second with the second-last, and so on.
An example plaintext to ciphertext using Atbash:
Plain: unfirm
Cipher: fmurin

Read more ...


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

Plain: unfirm

Read more ...


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 non-trivial 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: unfirm
cipher variations:

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 Latin-alphabet text x

An example plaintext to ciphertext using ROT13:

Plain: unfirm
Cipher: hasvez

Read more ...


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.
1 2 3 4 5
1 A B C D E
2 F G H I/J K
3 L M N O P
4 Q R S T U
5 V W X Y Z

Basic Form:
Plain: unfirm
Cipher: 543312422423

Extended Methods:
Method #1

Plaintext: unfirm
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
u n f i r m 
5 3 1 4 2 2 
4 3 2 2 4 3 
They are then read out in rows:
Then divided up into pairs again, and the pairs turned back into letters using the square:
Plain: unfirm
Cipher: pqgogo

Read more ...
Method #3

Plaintext: unfirm
method variations:
ocrgix crgixo rgixoc
gixocr ixocrg xocrgi

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: unfirm

all 720 cipher variations:
unfirm unfimr unfrim unfrmi unfmri unfmir unifrm unifmr unirfm unirmf unimrf
unimfr unrifm unrimf unrfim unrfmi unrmfi unrmif unmirf unmifr unmrif unmrfi
unmfri unmfir ufnirm ufnimr ufnrim ufnrmi ufnmri ufnmir ufinrm ufinmr ufirnm
ufirmn ufimrn ufimnr ufrinm ufrimn ufrnim ufrnmi ufrmni ufrmin ufmirn ufminr
ufmrin ufmrni ufmnri ufmnir uifnrm uifnmr uifrnm uifrmn uifmrn uifmnr uinfrm
uinfmr uinrfm uinrmf uinmrf uinmfr uirnfm uirnmf uirfnm uirfmn uirmfn uirmnf
uimnrf uimnfr uimrnf uimrfn uimfrn uimfnr urfinm urfimn urfnim urfnmi urfmni
urfmin urifnm urifmn urinfm urinmf urimnf urimfn urnifm urnimf urnfim urnfmi
urnmfi urnmif urminf urmifn urmnif urmnfi urmfni urmfin umfirn umfinr umfrin
umfrni umfnri umfnir umifrn umifnr umirfn umirnf uminrf uminfr umrifn umrinf
umrfin umrfni umrnfi umrnif umnirf umnifr umnrif umnrfi umnfri umnfir nufirm
nufimr nufrim nufrmi nufmri nufmir nuifrm nuifmr nuirfm nuirmf nuimrf nuimfr
nurifm nurimf nurfim nurfmi nurmfi nurmif numirf numifr numrif numrfi numfri
numfir nfuirm nfuimr nfurim nfurmi nfumri nfumir nfiurm nfiumr nfirum nfirmu
nfimru nfimur nfrium nfrimu nfruim nfrumi nfrmui nfrmiu nfmiru nfmiur nfmriu
nfmrui nfmuri nfmuir nifurm nifumr nifrum nifrmu nifmru nifmur niufrm niufmr
niurfm niurmf niumrf niumfr nirufm nirumf nirfum nirfmu nirmfu nirmuf nimurf
nimufr nimruf nimrfu nimfru nimfur nrfium nrfimu nrfuim nrfumi nrfmui nrfmiu
nrifum nrifmu nriufm nriumf nrimuf nrimfu nruifm nruimf nrufim nrufmi nrumfi
nrumif nrmiuf nrmifu nrmuif nrmufi nrmfui nrmfiu nmfiru nmfiur nmfriu nmfrui
nmfuri nmfuir nmifru nmifur nmirfu nmiruf nmiurf nmiufr nmrifu nmriuf nmrfiu
nmrfui nmrufi nmruif nmuirf nmuifr nmurif nmurfi nmufri nmufir fnuirm fnuimr
fnurim fnurmi fnumri fnumir fniurm fniumr fnirum fnirmu fnimru fnimur fnrium
fnrimu fnruim fnrumi fnrmui fnrmiu fnmiru fnmiur fnmriu fnmrui fnmuri fnmuir
funirm funimr funrim funrmi funmri funmir fuinrm fuinmr fuirnm fuirmn fuimrn
fuimnr furinm furimn furnim furnmi furmni furmin fumirn fuminr fumrin fumrni
fumnri fumnir fiunrm fiunmr fiurnm fiurmn fiumrn fiumnr finurm finumr finrum
finrmu finmru finmur firnum firnmu firunm firumn firmun firmnu fimnru fimnur
fimrnu fimrun fimurn fimunr fruinm fruimn frunim frunmi frumni frumin friunm
friumn frinum frinmu frimnu frimun frnium frnimu frnuim frnumi frnmui frnmiu
frminu frmiun frmniu frmnui frmuni frmuin fmuirn fmuinr fmurin fmurni fmunri
fmunir fmiurn fmiunr fmirun fmirnu fminru fminur fmriun fmrinu fmruin fmruni
fmrnui fmrniu fmniru fmniur fmnriu fmnrui fmnuri fmnuir infurm infumr infrum
infrmu infmru infmur inufrm inufmr inurfm inurmf inumrf inumfr inrufm inrumf
inrfum inrfmu inrmfu inrmuf inmurf inmufr inmruf inmrfu inmfru inmfur ifnurm
ifnumr ifnrum ifnrmu ifnmru ifnmur ifunrm ifunmr ifurnm ifurmn ifumrn ifumnr
ifrunm ifrumn ifrnum ifrnmu ifrmnu ifrmun ifmurn ifmunr ifmrun ifmrnu ifmnru
ifmnur iufnrm iufnmr iufrnm iufrmn iufmrn iufmnr iunfrm iunfmr iunrfm iunrmf
iunmrf iunmfr iurnfm iurnmf iurfnm iurfmn iurmfn iurmnf iumnrf iumnfr iumrnf
iumrfn iumfrn iumfnr irfunm irfumn irfnum irfnmu irfmnu irfmun irufnm irufmn
irunfm irunmf irumnf irumfn irnufm irnumf irnfum irnfmu irnmfu irnmuf irmunf
irmufn irmnuf irmnfu irmfnu irmfun imfurn imfunr imfrun imfrnu imfnru imfnur
imufrn imufnr imurfn imurnf imunrf imunfr imrufn imrunf imrfun imrfnu imrnfu
imrnuf imnurf imnufr imnruf imnrfu imnfru imnfur rnfium rnfimu rnfuim rnfumi
rnfmui rnfmiu rnifum rnifmu rniufm rniumf rnimuf rnimfu rnuifm rnuimf rnufim
rnufmi rnumfi rnumif rnmiuf rnmifu rnmuif rnmufi rnmfui rnmfiu rfnium rfnimu
rfnuim rfnumi rfnmui rfnmiu rfinum rfinmu rfiunm rfiumn rfimun rfimnu rfuinm
rfuimn rfunim rfunmi rfumni rfumin rfmiun rfminu rfmuin rfmuni rfmnui rfmniu
rifnum rifnmu rifunm rifumn rifmun rifmnu rinfum rinfmu rinufm rinumf rinmuf
rinmfu riunfm riunmf riufnm riufmn riumfn riumnf rimnuf rimnfu rimunf rimufn
rimfun rimfnu rufinm rufimn rufnim rufnmi rufmni rufmin ruifnm ruifmn ruinfm
ruinmf ruimnf ruimfn runifm runimf runfim runfmi runmfi runmif ruminf rumifn
rumnif rumnfi rumfni rumfin rmfiun rmfinu rmfuin rmfuni rmfnui rmfniu rmifun
rmifnu rmiufn rmiunf rminuf rminfu rmuifn rmuinf rmufin rmufni rmunfi rmunif
rmniuf rmnifu rmnuif rmnufi rmnfui rmnfiu mnfiru mnfiur mnfriu mnfrui mnfuri
mnfuir mnifru mnifur mnirfu mniruf mniurf mniufr mnrifu mnriuf mnrfiu mnrfui
mnrufi mnruif mnuirf mnuifr mnurif mnurfi mnufri mnufir mfniru mfniur mfnriu
mfnrui mfnuri mfnuir mfinru mfinur mfirnu mfirun mfiurn mfiunr mfrinu mfriun
mfrniu mfrnui mfruni mfruin mfuirn mfuinr mfurin mfurni mfunri mfunir mifnru
mifnur mifrnu mifrun mifurn mifunr minfru minfur minrfu minruf minurf minufr
mirnfu mirnuf mirfnu mirfun mirufn mirunf miunrf miunfr miurnf miurfn miufrn
miufnr mrfinu mrfiun mrfniu mrfnui mrfuni mrfuin mrifnu mrifun mrinfu mrinuf
mriunf mriufn mrnifu mrniuf mrnfiu mrnfui mrnufi mrnuif mruinf mruifn mrunif
mrunfi mrufni mrufin mufirn mufinr mufrin mufrni mufnri mufnir muifrn muifnr
muirfn muirnf muinrf muinfr murifn murinf murfin murfni murnfi murnif munirf
munifr munrif munrfi munfri munfir

Read more ...[1] , [2] , [3]

History of cryptography
2011 Easy Ciphers. All rights reserved. contact us