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: unsafe
cipher variations:
votbgf wpuchg xqvdih yrweji zsxfkj
atyglk buzhml cvainm dwbjon exckpo
fydlqp gzemrq hafnsr ibgots jchput
kdiqvu lejrwv mfksxw ngltyx ohmuzy
pinvaz qjowba rkpxcb slqydc tmrzed

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: unsafe
Cipher: fmhzuv

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: unsafe

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: unsafe
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: unsafe
Cipher: hafnsr

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: unsafe
Cipher: 543334111251

Extended Methods:
Method #1

Plaintext: unsafe
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 s a f e 
5 3 3 1 1 5 
4 3 4 1 2 1 
They are then read out in rows:
Then divided up into pairs again, and the pairs turned back into letters using the square:
Plain: unsafe
Cipher: pcvodb

Read more ...
Method #3

Plaintext: unsafe
method variations:
ondawv ndawvo dawvon
awvond wvonda vondaw

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: unsafe

all 720 cipher variations:
unsafe unsaef unsfae unsfea unsefa unseaf unasfe unasef unafse unafes unaefs
unaesf unfase unfaes unfsae unfsea unfesa unfeas uneafs uneasf unefas unefsa
unesfa unesaf usnafe usnaef usnfae usnfea usnefa usneaf usanfe usanef usafne
usafen usaefn usaenf usfane usfaen usfnae usfnea usfena usfean useafn useanf
usefan usefna usenfa usenaf uasnfe uasnef uasfne uasfen uasefn uasenf uansfe
uansef uanfse uanfes uanefs uanesf uafnse uafnes uafsne uafsen uafesn uafens
uaenfs uaensf uaefns uaefsn uaesfn uaesnf ufsane ufsaen ufsnae ufsnea ufsena
ufsean ufasne ufasen ufanse ufanes ufaens ufaesn ufnase ufnaes ufnsae ufnsea
ufnesa ufneas ufeans ufeasn ufenas ufensa ufesna ufesan uesafn uesanf uesfan
uesfna uesnfa uesnaf ueasfn ueasnf ueafsn ueafns ueanfs ueansf uefasn uefans
uefsan uefsna uefnsa uefnas uenafs uenasf uenfas uenfsa uensfa uensaf nusafe
nusaef nusfae nusfea nusefa nuseaf nuasfe nuasef nuafse nuafes nuaefs nuaesf
nufase nufaes nufsae nufsea nufesa nufeas nueafs nueasf nuefas nuefsa nuesfa
nuesaf nsuafe nsuaef nsufae nsufea nsuefa nsueaf nsaufe nsauef nsafue nsafeu
nsaefu nsaeuf nsfaue nsfaeu nsfuae nsfuea nsfeua nsfeau nseafu nseauf nsefau
nsefua nseufa nseuaf nasufe nasuef nasfue nasfeu nasefu naseuf nausfe nausef
naufse naufes nauefs nauesf nafuse nafues nafsue nafseu nafesu nafeus naeufs
naeusf naefus naefsu naesfu naesuf nfsaue nfsaeu nfsuae nfsuea nfseua nfseau
nfasue nfaseu nfause nfaues nfaeus nfaesu nfuase nfuaes nfusae nfusea nfuesa
nfueas nfeaus nfeasu nfeuas nfeusa nfesua nfesau nesafu nesauf nesfau nesfua
nesufa nesuaf neasfu neasuf neafsu neafus neaufs neausf nefasu nefaus nefsau
nefsua nefusa nefuas neuafs neuasf neufas neufsa neusfa neusaf snuafe snuaef
snufae snufea snuefa snueaf snaufe snauef snafue snafeu snaefu snaeuf snfaue
snfaeu snfuae snfuea snfeua snfeau sneafu sneauf snefau snefua sneufa sneuaf
sunafe sunaef sunfae sunfea sunefa suneaf suanfe suanef suafne suafen suaefn
suaenf sufane sufaen sufnae sufnea sufena sufean sueafn sueanf suefan suefna
suenfa suenaf saunfe saunef saufne saufen sauefn sauenf sanufe sanuef sanfue
sanfeu sanefu saneuf safnue safneu safune safuen safeun safenu saenfu saenuf
saefnu saefun saeufn saeunf sfuane sfuaen sfunae sfunea sfuena sfuean sfaune
sfauen sfanue sfaneu sfaenu sfaeun sfnaue sfnaeu sfnuae sfnuea sfneua sfneau
sfeanu sfeaun sfenau sfenua sfeuna sfeuan seuafn seuanf seufan seufna seunfa
seunaf seaufn seaunf seafun seafnu seanfu seanuf sefaun sefanu sefuan sefuna
sefnua sefnau senafu senauf senfau senfua senufa senuaf ansufe ansuef ansfue
ansfeu ansefu anseuf anusfe anusef anufse anufes anuefs anuesf anfuse anfues
anfsue anfseu anfesu anfeus aneufs aneusf anefus anefsu anesfu anesuf asnufe
asnuef asnfue asnfeu asnefu asneuf asunfe asunef asufne asufen asuefn asuenf
asfune asfuen asfnue asfneu asfenu asfeun aseufn aseunf asefun asefnu asenfu
asenuf ausnfe ausnef ausfne ausfen ausefn ausenf aunsfe aunsef aunfse aunfes
aunefs aunesf aufnse aufnes aufsne aufsen aufesn aufens auenfs auensf auefns
auefsn auesfn auesnf afsune afsuen afsnue afsneu afsenu afseun afusne afusen
afunse afunes afuens afuesn afnuse afnues afnsue afnseu afnesu afneus afeuns
afeusn afenus afensu afesnu afesun aesufn aesunf aesfun aesfnu aesnfu aesnuf
aeusfn aeusnf aeufsn aeufns aeunfs aeunsf aefusn aefuns aefsun aefsnu aefnsu
aefnus aenufs aenusf aenfus aenfsu aensfu aensuf fnsaue fnsaeu fnsuae fnsuea
fnseua fnseau fnasue fnaseu fnause fnaues fnaeus fnaesu fnuase fnuaes fnusae
fnusea fnuesa fnueas fneaus fneasu fneuas fneusa fnesua fnesau fsnaue fsnaeu
fsnuae fsnuea fsneua fsneau fsanue fsaneu fsaune fsauen fsaeun fsaenu fsuane
fsuaen fsunae fsunea fsuena fsuean fseaun fseanu fseuan fseuna fsenua fsenau
fasnue fasneu fasune fasuen faseun fasenu fansue fanseu fanuse fanues faneus
fanesu faunse faunes fausne fausen fauesn fauens faenus faensu faeuns faeusn
faesun faesnu fusane fusaen fusnae fusnea fusena fusean fuasne fuasen fuanse
fuanes fuaens fuaesn funase funaes funsae funsea funesa funeas fueans fueasn
fuenas fuensa fuesna fuesan fesaun fesanu fesuan fesuna fesnua fesnau feasun
feasnu feausn feauns feanus feansu feuasn feuans feusan feusna feunsa feunas
fenaus fenasu fenuas fenusa fensua fensau ensafu ensauf ensfau ensfua ensufa
ensuaf enasfu enasuf enafsu enafus enaufs enausf enfasu enfaus enfsau enfsua
enfusa enfuas enuafs enuasf enufas enufsa enusfa enusaf esnafu esnauf esnfau
esnfua esnufa esnuaf esanfu esanuf esafnu esafun esaufn esaunf esfanu esfaun
esfnau esfnua esfuna esfuan esuafn esuanf esufan esufna esunfa esunaf easnfu
easnuf easfnu easfun easufn easunf eansfu eansuf eanfsu eanfus eanufs eanusf
eafnsu eafnus eafsnu eafsun eafusn eafuns eaunfs eaunsf eaufns eaufsn eausfn
eausnf efsanu efsaun efsnau efsnua efsuna efsuan efasnu efasun efansu efanus
efauns efausn efnasu efnaus efnsau efnsua efnusa efnuas efuans efuasn efunas
efunsa efusna efusan eusafn eusanf eusfan eusfna eusnfa eusnaf euasfn euasnf
euafsn euafns euanfs euansf eufasn eufans eufsan eufsna eufnsa eufnas eunafs
eunasf eunfas eunfsa eunsfa eunsaf

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

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