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: forkey
cipher variations:
gpslfz hqtmga irunhb jsvoic ktwpjd
luxqke mvyrlf nwzsmg oxatnh pybuoi
qzcvpj radwqk sbexrl tcfysm udgztn
vehauo wfibvp xgjcwq yhkdxr zileys
ajmfzt bkngau clohbv dmpicw enqjdx

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: forkey
Cipher: ulipvb

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: forkey

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: forkey
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: forkey
Cipher: sbexrl

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: forkey
Cipher: 124324525145

Extended Methods:
Method #1

Plaintext: forkey
method variations:

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

Read more ...
Method #3

Plaintext: forkey
method variations:
rhywqe hywqer ywqerh
wqerhy qerhyw erhywq

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: forkey

all 720 cipher variations:
forkey forkye foreky foreyk foryek foryke fokrey fokrye fokery fokeyr fokyer
fokyre foekry foekyr foerky foeryk foeyrk foeykr foyker foykre foyekr foyerk
foyrek foyrke frokey frokye froeky froeyk froyek froyke frkoey frkoye frkeoy
frkeyo frkyeo frkyoe frekoy frekyo freoky freoyk freyok freyko frykeo frykoe
fryeko fryeok fryoek fryoke fkroey fkroye fkreoy fkreyo fkryeo fkryoe fkorey
fkorye fkoery fkoeyr fkoyer fkoyre fkeory fkeoyr fkeroy fkeryo fkeyro fkeyor
fkyoer fkyore fkyeor fkyero fkyreo fkyroe ferkoy ferkyo feroky feroyk feryok
feryko fekroy fekryo fekory fekoyr fekyor fekyro feokry feokyr feorky feoryk
feoyrk feoykr feykor feykro feyokr feyork feyrok feyrko fyrkeo fyrkoe fyreko
fyreok fyroek fyroke fykreo fykroe fykero fykeor fykoer fykore fyekro fyekor
fyerko fyerok fyeork fyeokr fyoker fyokre fyoekr fyoerk fyorek fyorke ofrkey
ofrkye ofreky ofreyk ofryek ofryke ofkrey ofkrye ofkery ofkeyr ofkyer ofkyre
ofekry ofekyr oferky oferyk ofeyrk ofeykr ofyker ofykre ofyekr ofyerk ofyrek
ofyrke orfkey orfkye orfeky orfeyk orfyek orfyke orkfey orkfye orkefy orkeyf
orkyef orkyfe orekfy orekyf orefky orefyk oreyfk oreykf orykef orykfe oryekf
oryefk oryfek oryfke okrfey okrfye okrefy okreyf okryef okryfe okfrey okfrye
okfery okfeyr okfyer okfyre okefry okefyr okerfy okeryf okeyrf okeyfr okyfer
okyfre okyefr okyerf okyref okyrfe oerkfy oerkyf oerfky oerfyk oeryfk oerykf
oekrfy oekryf oekfry oekfyr oekyfr oekyrf oefkry oefkyr oefrky oefryk oefyrk
oefykr oeykfr oeykrf oeyfkr oeyfrk oeyrfk oeyrkf oyrkef oyrkfe oyrekf oyrefk
oyrfek oyrfke oykref oykrfe oykerf oykefr oykfer oykfre oyekrf oyekfr oyerkf
oyerfk oyefrk oyefkr oyfker oyfkre oyfekr oyferk oyfrek oyfrke rofkey rofkye
rofeky rofeyk rofyek rofyke rokfey rokfye rokefy rokeyf rokyef rokyfe roekfy
roekyf roefky roefyk roeyfk roeykf roykef roykfe royekf royefk royfek royfke
rfokey rfokye rfoeky rfoeyk rfoyek rfoyke rfkoey rfkoye rfkeoy rfkeyo rfkyeo
rfkyoe rfekoy rfekyo rfeoky rfeoyk rfeyok rfeyko rfykeo rfykoe rfyeko rfyeok
rfyoek rfyoke rkfoey rkfoye rkfeoy rkfeyo rkfyeo rkfyoe rkofey rkofye rkoefy
rkoeyf rkoyef rkoyfe rkeofy rkeoyf rkefoy rkefyo rkeyfo rkeyof rkyoef rkyofe
rkyeof rkyefo rkyfeo rkyfoe refkoy refkyo refoky refoyk refyok refyko rekfoy
rekfyo rekofy rekoyf rekyof rekyfo reokfy reokyf reofky reofyk reoyfk reoykf
reykof reykfo reyokf reyofk reyfok reyfko ryfkeo ryfkoe ryfeko ryfeok ryfoek
ryfoke rykfeo rykfoe rykefo rykeof rykoef rykofe ryekfo ryekof ryefko ryefok
ryeofk ryeokf ryokef ryokfe ryoekf ryoefk ryofek ryofke korfey korfye korefy
koreyf koryef koryfe kofrey kofrye kofery kofeyr kofyer kofyre koefry koefyr
koerfy koeryf koeyrf koeyfr koyfer koyfre koyefr koyerf koyref koyrfe krofey
krofye kroefy kroeyf kroyef kroyfe krfoey krfoye krfeoy krfeyo krfyeo krfyoe
krefoy krefyo kreofy kreoyf kreyof kreyfo kryfeo kryfoe kryefo kryeof kryoef
kryofe kfroey kfroye kfreoy kfreyo kfryeo kfryoe kforey kforye kfoery kfoeyr
kfoyer kfoyre kfeory kfeoyr kferoy kferyo kfeyro kfeyor kfyoer kfyore kfyeor
kfyero kfyreo kfyroe kerfoy kerfyo kerofy keroyf keryof keryfo kefroy kefryo
kefory kefoyr kefyor kefyro keofry keofyr keorfy keoryf keoyrf keoyfr keyfor
keyfro keyofr keyorf keyrof keyrfo kyrfeo kyrfoe kyrefo kyreof kyroef kyrofe
kyfreo kyfroe kyfero kyfeor kyfoer kyfore kyefro kyefor kyerfo kyerof kyeorf
kyeofr kyofer kyofre kyoefr kyoerf kyoref kyorfe eorkfy eorkyf eorfky eorfyk
eoryfk eorykf eokrfy eokryf eokfry eokfyr eokyfr eokyrf eofkry eofkyr eofrky
eofryk eofyrk eofykr eoykfr eoykrf eoyfkr eoyfrk eoyrfk eoyrkf erokfy erokyf
erofky erofyk eroyfk eroykf erkofy erkoyf erkfoy erkfyo erkyfo erkyof erfkoy
erfkyo erfoky erfoyk erfyok erfyko erykfo erykof eryfko eryfok eryofk eryokf
ekrofy ekroyf ekrfoy ekrfyo ekryfo ekryof ekorfy ekoryf ekofry ekofyr ekoyfr
ekoyrf ekfory ekfoyr ekfroy ekfryo ekfyro ekfyor ekyofr ekyorf ekyfor ekyfro
ekyrfo ekyrof efrkoy efrkyo efroky efroyk efryok efryko efkroy efkryo efkory
efkoyr efkyor efkyro efokry efokyr eforky eforyk efoyrk efoykr efykor efykro
efyokr efyork efyrok efyrko eyrkfo eyrkof eyrfko eyrfok eyrofk eyrokf eykrfo
eykrof eykfro eykfor eykofr eykorf eyfkro eyfkor eyfrko eyfrok eyfork eyfokr
eyokfr eyokrf eyofkr eyofrk eyorfk eyorkf yorkef yorkfe yorekf yorefk yorfek
yorfke yokref yokrfe yokerf yokefr yokfer yokfre yoekrf yoekfr yoerkf yoerfk
yoefrk yoefkr yofker yofkre yofekr yoferk yofrek yofrke yrokef yrokfe yroekf
yroefk yrofek yrofke yrkoef yrkofe yrkeof yrkefo yrkfeo yrkfoe yrekof yrekfo
yreokf yreofk yrefok yrefko yrfkeo yrfkoe yrfeko yrfeok yrfoek yrfoke ykroef
ykrofe ykreof ykrefo ykrfeo ykrfoe ykoref ykorfe ykoerf ykoefr ykofer ykofre
ykeorf ykeofr ykerof ykerfo ykefro ykefor ykfoer ykfore ykfeor ykfero ykfreo
ykfroe yerkof yerkfo yerokf yerofk yerfok yerfko yekrof yekrfo yekorf yekofr
yekfor yekfro yeokrf yeokfr yeorkf yeorfk yeofrk yeofkr yefkor yefkro yefokr
yefork yefrok yefrko yfrkeo yfrkoe yfreko yfreok yfroek yfroke yfkreo yfkroe
yfkero yfkeor yfkoer yfkore yfekro yfekor yferko yferok yfeork yfeokr yfoker
yfokre yfoekr yfoerk yforek yforke

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

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