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: atnick
cipher variations:
buojdl cvpkem dwqlfn exrmgo fysnhp
gztoiq haupjr ibvqks jcwrlt kdxsmu
leytnv mfzuow ngavpx ohbwqy picxrz
qjdysa rkeztb slfauc tmgbvd unhcwe
voidxf wpjeyg xqkfzh yrlgai zsmhbj

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: atnick
Cipher: zgmrxp

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: atnick

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: atnick
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: atnick
Cipher: ngavpx

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: atnick
Cipher: 114433423152

Extended Methods:
Method #1

Plaintext: atnick
method variations:

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

Read more ...
Method #3

Plaintext: atnick
method variations:
qosmvb osmvbq smvbqo
mvbqos vbqosm bqosmv

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: atnick

all 720 cipher variations:
atnick atnikc atncik atncki atnkci atnkic atinck atinkc aticnk atickn atikcn
atiknc atcink atcikn atcnik atcnki atckni atckin atkicn atkinc atkcin atkcni
atknci atknic antick antikc antcik antcki antkci antkic anitck anitkc anictk
anickt anikct aniktc ancitk ancikt anctik anctki anckti anckit ankict ankitc
ankcit ankcti anktci anktic aintck aintkc ainctk ainckt ainkct ainktc aitnck
aitnkc aitcnk aitckn aitkcn aitknc aictnk aictkn aicntk aicnkt aicknt aicktn
aiktcn aiktnc aikctn aikcnt aiknct aikntc acnitk acnikt acntik acntki acnkti
acnkit acintk acinkt acitnk acitkn aciktn aciknt actink actikn actnik actnki
actkni actkin ackitn ackint acktin acktni acknti acknit aknict aknitc akncit
akncti akntci akntic akinct akintc akicnt akictn akitcn akitnc akcint akcitn
akcnit akcnti akctni akctin akticn aktinc aktcin aktcni aktnci aktnic tanick
tanikc tancik tancki tankci tankic tainck tainkc taicnk taickn taikcn taiknc
tacink tacikn tacnik tacnki tackni tackin takicn takinc takcin takcni taknci
taknic tnaick tnaikc tnacik tnacki tnakci tnakic tniack tniakc tnicak tnicka
tnikca tnikac tnciak tncika tncaik tncaki tnckai tnckia tnkica tnkiac tnkcia
tnkcai tnkaci tnkaic tinack tinakc tincak tincka tinkca tinkac tianck tiankc
tiacnk tiackn tiakcn tiaknc ticank ticakn ticnak ticnka tickna tickan tikacn
tikanc tikcan tikcna tiknca tiknac tcniak tcnika tcnaik tcnaki tcnkai tcnkia
tcinak tcinka tciank tciakn tcikan tcikna tcaink tcaikn tcanik tcanki tcakni
tcakin tckian tckina tckain tckani tcknai tcknia tknica tkniac tkncia tkncai
tknaci tknaic tkinca tkinac tkicna tkican tkiacn tkianc tkcina tkcian tkcnia
tkcnai tkcani tkcain tkaicn tkainc tkacin tkacni tkanci tkanic ntaick ntaikc
ntacik ntacki ntakci ntakic ntiack ntiakc nticak nticka ntikca ntikac ntciak
ntcika ntcaik ntcaki ntckai ntckia ntkica ntkiac ntkcia ntkcai ntkaci ntkaic
natick natikc natcik natcki natkci natkic naitck naitkc naictk naickt naikct
naiktc nacitk nacikt nactik nactki nackti nackit nakict nakitc nakcit nakcti
naktci naktic niatck niatkc niactk niackt niakct niaktc nitack nitakc nitcak
nitcka nitkca nitkac nictak nictka nicatk nicakt nickat nickta niktca niktac
nikcta nikcat nikact nikatc ncaitk ncaikt ncatik ncatki ncakti ncakit nciatk
nciakt ncitak ncitka ncikta ncikat nctiak nctika nctaik nctaki nctkai nctkia
nckita nckiat ncktia ncktai nckati nckait nkaict nkaitc nkacit nkacti nkatci
nkatic nkiact nkiatc nkicat nkicta nkitca nkitac nkciat nkcita nkcait nkcati
nkctai nkctia nktica nktiac nktcia nktcai nktaci nktaic itnack itnakc itncak
itncka itnkca itnkac itanck itankc itacnk itackn itakcn itaknc itcank itcakn
itcnak itcnka itckna itckan itkacn itkanc itkcan itkcna itknca itknac intack
intakc intcak intcka intkca intkac inatck inatkc inactk inackt inakct inaktc
incatk incakt inctak inctka inckta inckat inkact inkatc inkcat inkcta inktca
inktac iantck iantkc ianctk ianckt iankct ianktc iatnck iatnkc iatcnk iatckn
iatkcn iatknc iactnk iactkn iacntk iacnkt iacknt iacktn iaktcn iaktnc iakctn
iakcnt iaknct iakntc icnatk icnakt icntak icntka icnkta icnkat icantk icankt
icatnk icatkn icaktn icaknt ictank ictakn ictnak ictnka ictkna ictkan ickatn
ickant icktan icktna icknta icknat iknact iknatc ikncat ikncta ikntca ikntac
ikanct ikantc ikacnt ikactn ikatcn ikatnc ikcant ikcatn ikcnat ikcnta ikctna
ikctan iktacn iktanc iktcan iktcna iktnca iktnac ctniak ctnika ctnaik ctnaki
ctnkai ctnkia ctinak ctinka ctiank ctiakn ctikan ctikna ctaink ctaikn ctanik
ctanki ctakni ctakin ctkian ctkina ctkain ctkani ctknai ctknia cntiak cntika
cntaik cntaki cntkai cntkia cnitak cnitka cniatk cniakt cnikat cnikta cnaitk
cnaikt cnatik cnatki cnakti cnakit cnkiat cnkita cnkait cnkati cnktai cnktia
cintak cintka cinatk cinakt cinkat cinkta citnak citnka citank citakn citkan
citkna ciatnk ciatkn ciantk ciankt ciaknt ciaktn ciktan ciktna cikatn cikant
ciknat ciknta canitk canikt cantik cantki cankti cankit caintk cainkt caitnk
caitkn caiktn caiknt catink catikn catnik catnki catkni catkin cakitn cakint
caktin caktni caknti caknit ckniat cknita cknait cknati ckntai ckntia ckinat
ckinta ckiant ckiatn ckitan ckitna ckaint ckaitn ckanit ckanti ckatni ckatin
cktian cktina cktain cktani cktnai cktnia ktnica ktniac ktncia ktncai ktnaci
ktnaic ktinca ktinac kticna ktican ktiacn ktianc ktcina ktcian ktcnia ktcnai
ktcani ktcain ktaicn ktainc ktacin ktacni ktanci ktanic kntica kntiac kntcia
kntcai kntaci kntaic knitca knitac knicta knicat kniact kniatc kncita knciat
knctia knctai kncati kncait knaict knaitc knacit knacti knatci knatic kintca
kintac kincta kincat kinact kinatc kitnca kitnac kitcna kitcan kitacn kitanc
kictna kictan kicnta kicnat kicant kicatn kiatcn kiatnc kiactn kiacnt kianct
kiantc kcnita kcniat kcntia kcntai kcnati kcnait kcinta kcinat kcitna kcitan
kciatn kciant kctina kctian kctnia kctnai kctani kctain kcaitn kcaint kcatin
kcatni kcanti kcanit kanict kanitc kancit kancti kantci kantic kainct kaintc
kaicnt kaictn kaitcn kaitnc kacint kacitn kacnit kacnti kactni kactin katicn
katinc katcin katcni katnci katnic

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

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