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: rhombi
cipher variations:
sipncj tjqodk ukrpel vlsqfm wmtrgn
xnusho yovtip zpwujq aqxvkr brywls
cszxmt dtaynu eubzov fvcapw gwdbqx
hxecry iyfdsz jzgeta kahfub lbigvc
mcjhwd ndkixe oeljyf pfmkzg qgnlah

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: rhombi
Cipher: islnyr

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: rhombi

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: rhombi
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: rhombi
Cipher: eubzov

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: rhombi
Cipher: 243243232142

Extended Methods:
Method #1

Plaintext: rhombi
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
r h o m b i 
2 3 4 2 2 4 
4 2 3 3 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: rhombi
Cipher: mirinf

Read more ...
Method #3

Plaintext: rhombi
method variations:
orhhqg rhhqgo hhqgor
hqgorh qgorhh gorhhq

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: rhombi

all 720 cipher variations:
rhombi rhomib rhobmi rhobim rhoibm rhoimb rhmobi rhmoib rhmboi rhmbio rhmibo
rhmiob rhbmoi rhbmio rhbomi rhboim rhbiom rhbimo rhimbo rhimob rhibmo rhibom
rhiobm rhiomb rohmbi rohmib rohbmi rohbim rohibm rohimb romhbi romhib rombhi
rombih romibh romihb robmhi robmih robhmi robhim robihm robimh roimbh roimhb
roibmh roibhm roihbm roihmb rmohbi rmohib rmobhi rmobih rmoibh rmoihb rmhobi
rmhoib rmhboi rmhbio rmhibo rmhiob rmbhoi rmbhio rmbohi rmboih rmbioh rmbiho
rmihbo rmihob rmibho rmiboh rmiobh rmiohb rbomhi rbomih rbohmi rbohim rboihm
rboimh rbmohi rbmoih rbmhoi rbmhio rbmiho rbmioh rbhmoi rbhmio rbhomi rbhoim
rbhiom rbhimo rbimho rbimoh rbihmo rbihom rbiohm rbiomh riombh riomhb riobmh
riobhm riohbm riohmb rimobh rimohb rimboh rimbho rimhbo rimhob ribmoh ribmho
ribomh ribohm ribhom ribhmo rihmbo rihmob rihbmo rihbom rihobm rihomb hrombi
hromib hrobmi hrobim hroibm hroimb hrmobi hrmoib hrmboi hrmbio hrmibo hrmiob
hrbmoi hrbmio hrbomi hrboim hrbiom hrbimo hrimbo hrimob hribmo hribom hriobm
hriomb hormbi hormib horbmi horbim horibm horimb homrbi homrib hombri hombir
homibr homirb hobmri hobmir hobrmi hobrim hobirm hobimr hoimbr hoimrb hoibmr
hoibrm hoirbm hoirmb hmorbi hmorib hmobri hmobir hmoibr hmoirb hmrobi hmroib
hmrboi hmrbio hmribo hmriob hmbroi hmbrio hmbori hmboir hmbior hmbiro hmirbo
hmirob hmibro hmibor hmiobr hmiorb hbomri hbomir hbormi hborim hboirm hboimr
hbmori hbmoir hbmroi hbmrio hbmiro hbmior hbrmoi hbrmio hbromi hbroim hbriom
hbrimo hbimro hbimor hbirmo hbirom hbiorm hbiomr hiombr hiomrb hiobmr hiobrm
hiorbm hiormb himobr himorb himbor himbro himrbo himrob hibmor hibmro hibomr
hiborm hibrom hibrmo hirmbo hirmob hirbmo hirbom hirobm hiromb ohrmbi ohrmib
ohrbmi ohrbim ohribm ohrimb ohmrbi ohmrib ohmbri ohmbir ohmibr ohmirb ohbmri
ohbmir ohbrmi ohbrim ohbirm ohbimr ohimbr ohimrb ohibmr ohibrm ohirbm ohirmb
orhmbi orhmib orhbmi orhbim orhibm orhimb ormhbi ormhib ormbhi ormbih ormibh
ormihb orbmhi orbmih orbhmi orbhim orbihm orbimh orimbh orimhb oribmh oribhm
orihbm orihmb omrhbi omrhib omrbhi omrbih omribh omrihb omhrbi omhrib omhbri
omhbir omhibr omhirb ombhri ombhir ombrhi ombrih ombirh ombihr omihbr omihrb
omibhr omibrh omirbh omirhb obrmhi obrmih obrhmi obrhim obrihm obrimh obmrhi
obmrih obmhri obmhir obmihr obmirh obhmri obhmir obhrmi obhrim obhirm obhimr
obimhr obimrh obihmr obihrm obirhm obirmh oirmbh oirmhb oirbmh oirbhm oirhbm
oirhmb oimrbh oimrhb oimbrh oimbhr oimhbr oimhrb oibmrh oibmhr oibrmh oibrhm
oibhrm oibhmr oihmbr oihmrb oihbmr oihbrm oihrbm oihrmb mhorbi mhorib mhobri
mhobir mhoibr mhoirb mhrobi mhroib mhrboi mhrbio mhribo mhriob mhbroi mhbrio
mhbori mhboir mhbior mhbiro mhirbo mhirob mhibro mhibor mhiobr mhiorb mohrbi
mohrib mohbri mohbir mohibr mohirb morhbi morhib morbhi morbih moribh morihb
mobrhi mobrih mobhri mobhir mobihr mobirh moirbh moirhb moibrh moibhr moihbr
moihrb mrohbi mrohib mrobhi mrobih mroibh mroihb mrhobi mrhoib mrhboi mrhbio
mrhibo mrhiob mrbhoi mrbhio mrbohi mrboih mrbioh mrbiho mrihbo mrihob mribho
mriboh mriobh mriohb mborhi mborih mbohri mbohir mboihr mboirh mbrohi mbroih
mbrhoi mbrhio mbriho mbrioh mbhroi mbhrio mbhori mbhoir mbhior mbhiro mbirho
mbiroh mbihro mbihor mbiohr mbiorh miorbh miorhb miobrh miobhr miohbr miohrb
mirobh mirohb mirboh mirbho mirhbo mirhob mibroh mibrho miborh mibohr mibhor
mibhro mihrbo mihrob mihbro mihbor mihobr mihorb bhomri bhomir bhormi bhorim
bhoirm bhoimr bhmori bhmoir bhmroi bhmrio bhmiro bhmior bhrmoi bhrmio bhromi
bhroim bhriom bhrimo bhimro bhimor bhirmo bhirom bhiorm bhiomr bohmri bohmir
bohrmi bohrim bohirm bohimr bomhri bomhir bomrhi bomrih bomirh bomihr bormhi
bormih borhmi borhim borihm borimh boimrh boimhr boirmh boirhm boihrm boihmr
bmohri bmohir bmorhi bmorih bmoirh bmoihr bmhori bmhoir bmhroi bmhrio bmhiro
bmhior bmrhoi bmrhio bmrohi bmroih bmrioh bmriho bmihro bmihor bmirho bmiroh
bmiorh bmiohr bromhi bromih brohmi brohim broihm broimh brmohi brmoih brmhoi
brmhio brmiho brmioh brhmoi brhmio brhomi brhoim brhiom brhimo brimho brimoh
brihmo brihom briohm briomh biomrh biomhr biormh biorhm biohrm biohmr bimorh
bimohr bimroh bimrho bimhro bimhor birmoh birmho biromh birohm birhom birhmo
bihmro bihmor bihrmo bihrom bihorm bihomr ihombr ihomrb ihobmr ihobrm ihorbm
ihormb ihmobr ihmorb ihmbor ihmbro ihmrbo ihmrob ihbmor ihbmro ihbomr ihborm
ihbrom ihbrmo ihrmbo ihrmob ihrbmo ihrbom ihrobm ihromb iohmbr iohmrb iohbmr
iohbrm iohrbm iohrmb iomhbr iomhrb iombhr iombrh iomrbh iomrhb iobmhr iobmrh
iobhmr iobhrm iobrhm iobrmh iormbh iormhb iorbmh iorbhm iorhbm iorhmb imohbr
imohrb imobhr imobrh imorbh imorhb imhobr imhorb imhbor imhbro imhrbo imhrob
imbhor imbhro imbohr imborh imbroh imbrho imrhbo imrhob imrbho imrboh imrobh
imrohb ibomhr ibomrh ibohmr ibohrm iborhm ibormh ibmohr ibmorh ibmhor ibmhro
ibmrho ibmroh ibhmor ibhmro ibhomr ibhorm ibhrom ibhrmo ibrmho ibrmoh ibrhmo
ibrhom ibrohm ibromh irombh iromhb irobmh irobhm irohbm irohmb irmobh irmohb
irmboh irmbho irmhbo irmhob irbmoh irbmho irbomh irbohm irbhom irbhmo irhmbo
irhmob irhbmo irhbom irhobm irhomb

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

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