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: rogued
cipher variations:
sphvfe tqiwgf urjxhg vskyih wtlzji
xumakj yvnblk zwocml axpdnm byqeon
czrfpo dasgqp ebthrq fcuisr gdvjts
hewkut ifxlvu jgymwv khznxw liaoyx
mjbpzy nkcqaz oldrba pmescb qnftdc

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: rogued
Cipher: iltfvw

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: rogued

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: rogued
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: rogued
Cipher: ebthrq

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: rogued
Cipher: 244322545141

Extended Methods:
Method #1

Plaintext: rogued
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
r o g u e d 
2 4 2 5 5 4 
4 3 2 4 1 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: rogued
Cipher: rwuora

Read more ...
Method #3

Plaintext: rogued
method variations:
thwyqf hwyqft wyqfth
yqfthw qfthwy fthwyq

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: rogued

all 720 cipher variations:
rogued rogude rogeud rogedu rogdeu rogdue rouged rougde rouegd rouedg roudeg
roudge roeugd roeudg roegud roegdu roedgu roedug rodueg roduge rodeug rodegu
rodgeu rodgue rgoued rgoude rgoeud rgoedu rgodeu rgodue rguoed rguode rgueod
rguedo rgudeo rgudoe rgeuod rgeudo rgeoud rgeodu rgedou rgeduo rgdueo rgduoe
rgdeuo rgdeou rgdoeu rgdoue rugoed rugode rugeod rugedo rugdeo rugdoe ruoged
ruogde ruoegd ruoedg ruodeg ruodge rueogd rueodg ruegod ruegdo ruedgo ruedog
rudoeg rudoge rudeog rudego rudgeo rudgoe reguod regudo regoud regodu regdou
regduo reugod reugdo reuogd reuodg reudog reudgo reougd reoudg reogud reogdu
reodgu reodug reduog redugo redoug redogu redgou redguo rdgueo rdguoe rdgeuo
rdgeou rdgoeu rdgoue rdugeo rdugoe rduego rdueog rduoeg rduoge rdeugo rdeuog
rdeguo rdegou rdeogu rdeoug rdoueg rdouge rdoeug rdoegu rdogeu rdogue orgued
orgude orgeud orgedu orgdeu orgdue oruged orugde oruegd oruedg orudeg orudge
oreugd oreudg oregud oregdu oredgu oredug ordueg orduge ordeug ordegu ordgeu
ordgue ogrued ogrude ogreud ogredu ogrdeu ogrdue ogured ogurde oguerd oguedr
oguder ogudre ogeurd ogeudr ogerud ogerdu ogedru ogedur ogduer ogdure ogdeur
ogderu ogdreu ogdrue ougred ougrde ougerd ougedr ougder ougdre ourged ourgde
ouregd ouredg ourdeg ourdge ouergd ouerdg ouegrd ouegdr ouedgr ouedrg oudreg
oudrge ouderg oudegr oudger oudgre oegurd oegudr oegrud oegrdu oegdru oegdur
oeugrd oeugdr oeurgd oeurdg oeudrg oeudgr oerugd oerudg oergud oergdu oerdgu
oerdug oedurg oedugr oedrug oedrgu oedgru oedgur odguer odgure odgeur odgeru
odgreu odgrue oduger odugre oduegr oduerg odureg odurge odeugr odeurg odegur
odegru odergu oderug odrueg odruge odreug odregu odrgeu odrgue gorued gorude
goreud goredu gordeu gordue goured gourde gouerd gouedr gouder goudre goeurd
goeudr goerud goerdu goedru goedur goduer godure godeur goderu godreu godrue
groued groude groeud groedu grodeu grodue gruoed gruode grueod gruedo grudeo
grudoe greuod greudo greoud greodu gredou greduo grdueo grduoe grdeuo grdeou
grdoeu grdoue guroed gurode gureod guredo gurdeo gurdoe guored guorde guoerd
guoedr guoder guodre gueord gueodr guerod guerdo guedro guedor gudoer gudore
gudeor gudero gudreo gudroe geruod gerudo geroud gerodu gerdou gerduo geurod
geurdo geuord geuodr geudor geudro geourd geoudr georud geordu geodru geodur
geduor geduro gedour gedoru gedrou gedruo gdrueo gdruoe gdreuo gdreou gdroeu
gdroue gdureo gduroe gduero gdueor gduoer gduore gdeuro gdeuor gderuo gderou
gdeoru gdeour gdouer gdoure gdoeur gdoeru gdoreu gdorue uogred uogrde uogerd
uogedr uogder uogdre uorged uorgde uoregd uoredg uordeg uordge uoergd uoerdg
uoegrd uoegdr uoedgr uoedrg uodreg uodrge uoderg uodegr uodger uodgre ugored
ugorde ugoerd ugoedr ugoder ugodre ugroed ugrode ugreod ugredo ugrdeo ugrdoe
ugerod ugerdo ugeord ugeodr ugedor ugedro ugdreo ugdroe ugdero ugdeor ugdoer
ugdore urgoed urgode urgeod urgedo urgdeo urgdoe uroged urogde uroegd uroedg
urodeg urodge ureogd ureodg uregod uregdo uredgo uredog urdoeg urdoge urdeog
urdego urdgeo urdgoe uegrod uegrdo uegord uegodr uegdor uegdro uergod uergdo
uerogd uerodg uerdog uerdgo ueorgd ueordg ueogrd ueogdr ueodgr ueodrg uedrog
uedrgo uedorg uedogr uedgor uedgro udgreo udgroe udgero udgeor udgoer udgore
udrgeo udrgoe udrego udreog udroeg udroge udergo uderog udegro udegor udeogr
udeorg udoreg udorge udoerg udoegr udoger udogre eogurd eogudr eogrud eogrdu
eogdru eogdur eougrd eougdr eourgd eourdg eoudrg eoudgr eorugd eorudg eorgud
eorgdu eordgu eordug eodurg eodugr eodrug eodrgu eodgru eodgur egourd egoudr
egorud egordu egodru egodur eguord eguodr egurod egurdo egudro egudor egruod
egrudo egroud egrodu egrdou egrduo egduro egduor egdruo egdrou egdoru egdour
eugord eugodr eugrod eugrdo eugdro eugdor euogrd euogdr euorgd euordg euodrg
euodgr eurogd eurodg eurgod eurgdo eurdgo eurdog eudorg eudogr eudrog eudrgo
eudgro eudgor erguod ergudo ergoud ergodu ergdou ergduo erugod erugdo eruogd
eruodg erudog erudgo erougd eroudg erogud erogdu erodgu erodug erduog erdugo
erdoug erdogu erdgou erdguo edguro edguor edgruo edgrou edgoru edgour edugro
edugor edurgo edurog eduorg eduogr edrugo edruog edrguo edrgou edrogu edroug
edourg edougr edorug edorgu edogru edogur doguer dogure dogeur dogeru dogreu
dogrue douger dougre douegr douerg doureg dourge doeugr doeurg doegur doegru
doergu doerug dorueg doruge doreug doregu dorgeu dorgue dgouer dgoure dgoeur
dgoeru dgoreu dgorue dguoer dguore dgueor dguero dgureo dguroe dgeuor dgeuro
dgeour dgeoru dgerou dgeruo dgrueo dgruoe dgreuo dgreou dgroeu dgroue dugoer
dugore dugeor dugero dugreo dugroe duoger duogre duoegr duoerg duoreg duorge
dueogr dueorg duegor duegro duergo duerog duroeg duroge dureog durego durgeo
durgoe deguor deguro degour degoru degrou degruo deugor deugro deuogr deuorg
deurog deurgo deougr deourg deogur deogru deorgu deorug deruog derugo deroug
derogu dergou derguo drgueo drguoe drgeuo drgeou drgoeu drgoue drugeo drugoe
druego drueog druoeg druoge dreugo dreuog dreguo dregou dreogu dreoug droueg
drouge droeug droegu drogeu drogue

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

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