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: pleats
cipher variations:
qmfbut rngcvu sohdwv tpiexw uqjfyx
vrkgzy wslhaz xtmiba yunjcb zvokdc
awpled bxqmfe cyrngf dzsohg eatpih
fbuqji gcvrkj hdwslk iextml jfyunm
kgzvon lhawpo mibxqp njcyrq okdzsr

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: pleats
Cipher: kovzgh

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: pleats

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: pleats
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: pleats
Cipher: cyrngf

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: pleats
Cipher: 531351114434

Extended Methods:
Method #1

Plaintext: pleats
method variations:

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

Read more ...
Method #3

Plaintext: pleats
method variations:
cxaqoy xaqoyc aqoycx
qoycxa oycxaq ycxaqo

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: pleats

all 720 cipher variations:
pleats pleast pletas pletsa plesta plesat plaets plaest plates platse plaste
plaset pltaes pltase plteas pltesa pltsea pltsae plsate plsaet plstae plstea
plseta plseat pelats pelast peltas peltsa pelsta pelsat pealts pealst peatls
peatsl peastl peaslt petals petasl petlas petlsa petsla petsal pesatl pesalt
pestal pestla peslta peslat paelts paelst paetls paetsl paestl paeslt palets
palest paltes paltse palste palset patles patlse patels patesl patsel patsle
paslte paslet pastle pastel pasetl paselt pteals pteasl ptelas ptelsa ptesla
ptesal ptaels ptaesl ptales ptalse ptasle ptasel ptlaes ptlase ptleas ptlesa
ptlsea ptlsae ptsale ptsael ptslae ptslea ptsela ptseal pseatl psealt psetal
psetla pselta pselat psaetl psaelt psatel psatle psalte psalet pstael pstale
psteal pstela pstlea pstlae pslate pslaet psltae psltea psleta psleat lpeats
lpeast lpetas lpetsa lpesta lpesat lpaets lpaest lpates lpatse lpaste lpaset
lptaes lptase lpteas lptesa lptsea lptsae lpsate lpsaet lpstae lpstea lpseta
lpseat lepats lepast leptas leptsa lepsta lepsat leapts leapst leatps leatsp
leastp leaspt letaps letasp letpas letpsa letspa letsap lesatp lesapt lestap
lestpa lespta lespat laepts laepst laetps laetsp laestp laespt lapets lapest
laptes laptse lapste lapset latpes latpse lateps latesp latsep latspe laspte
laspet lastpe lastep lasetp lasept lteaps lteasp ltepas ltepsa ltespa ltesap
ltaeps ltaesp ltapes ltapse ltaspe ltasep ltpaes ltpase ltpeas ltpesa ltpsea
ltpsae ltsape ltsaep ltspae ltspea ltsepa ltseap lseatp lseapt lsetap lsetpa
lsepta lsepat lsaetp lsaept lsatep lsatpe lsapte lsapet lstaep lstape lsteap
lstepa lstpea lstpae lspate lspaet lsptae lsptea lspeta lspeat elpats elpast
elptas elptsa elpsta elpsat elapts elapst elatps elatsp elastp elaspt eltaps
eltasp eltpas eltpsa eltspa eltsap elsatp elsapt elstap elstpa elspta elspat
eplats eplast epltas epltsa eplsta eplsat epalts epalst epatls epatsl epastl
epaslt eptals eptasl eptlas eptlsa eptsla eptsal epsatl epsalt epstal epstla
epslta epslat eaplts eaplst eaptls eaptsl eapstl eapslt ealpts ealpst ealtps
ealtsp ealstp ealspt eatlps eatlsp eatpls eatpsl eatspl eatslp easltp easlpt
eastlp eastpl easptl easplt etpals etpasl etplas etplsa etpsla etpsal etapls
etapsl etalps etalsp etaslp etaspl etlaps etlasp etlpas etlpsa etlspa etlsap
etsalp etsapl etslap etslpa etspla etspal espatl espalt esptal esptla esplta
esplat esaptl esaplt esatpl esatlp esaltp esalpt estapl estalp estpal estpla
estlpa estlap eslatp eslapt esltap esltpa eslpta eslpat alepts alepst aletps
aletsp alestp alespt alpets alpest alptes alptse alpste alpset altpes altpse
alteps altesp altsep altspe alspte alspet alstpe alstep alsetp alsept aelpts
aelpst aeltps aeltsp aelstp aelspt aeplts aeplst aeptls aeptsl aepstl aepslt
aetpls aetpsl aetlps aetlsp aetslp aetspl aesptl aesplt aestpl aestlp aesltp
aeslpt apelts apelst apetls apetsl apestl apeslt aplets aplest apltes apltse
aplste aplset aptles aptlse aptels aptesl aptsel aptsle apslte apslet apstle
apstel apsetl apselt atepls atepsl atelps atelsp ateslp atespl atpels atpesl
atples atplse atpsle atpsel atlpes atlpse atleps atlesp atlsep atlspe atsple
atspel atslpe atslep atselp atsepl aseptl aseplt asetpl asetlp aseltp aselpt
aspetl aspelt asptel asptle asplte asplet astpel astple astepl astelp astlep
astlpe aslpte aslpet asltpe asltep asletp aslept tleaps tleasp tlepas tlepsa
tlespa tlesap tlaeps tlaesp tlapes tlapse tlaspe tlasep tlpaes tlpase tlpeas
tlpesa tlpsea tlpsae tlsape tlsaep tlspae tlspea tlsepa tlseap telaps telasp
telpas telpsa telspa telsap tealps tealsp teapls teapsl teaspl teaslp tepals
tepasl teplas teplsa tepsla tepsal tesapl tesalp tespal tespla teslpa teslap
taelps taelsp taepls taepsl taespl taeslp taleps talesp talpes talpse talspe
talsep taples taplse tapels tapesl tapsel tapsle taslpe taslep tasple taspel
tasepl taselp tpeals tpeasl tpelas tpelsa tpesla tpesal tpaels tpaesl tpales
tpalse tpasle tpasel tplaes tplase tpleas tplesa tplsea tplsae tpsale tpsael
tpslae tpslea tpsela tpseal tseapl tsealp tsepal tsepla tselpa tselap tsaepl
tsaelp tsapel tsaple tsalpe tsalep tspael tspale tspeal tspela tsplea tsplae
tslape tslaep tslpae tslpea tslepa tsleap sleatp sleapt sletap sletpa slepta
slepat slaetp slaept slatep slatpe slapte slapet sltaep sltape slteap sltepa
sltpea sltpae slpate slpaet slptae slptea slpeta slpeat selatp selapt seltap
seltpa selpta selpat sealtp sealpt seatlp seatpl seaptl seaplt setalp setapl
setlap setlpa setpla setpal sepatl sepalt septal septla seplta seplat saeltp
saelpt saetlp saetpl saeptl saeplt saletp salept saltep saltpe salpte salpet
satlep satlpe satelp satepl satpel satple saplte saplet saptle saptel sapetl
sapelt stealp steapl stelap stelpa stepla stepal staelp staepl stalep stalpe
staple stapel stlaep stlape stleap stlepa stlpea stlpae stpale stpael stplae
stplea stpela stpeal speatl spealt spetal spetla spelta spelat spaetl spaelt
spatel spatle spalte spalet sptael sptale spteal sptela sptlea sptlae splate
splaet spltae spltea spleta spleat

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

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