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: tchula
cipher variations:
udivmb vejwnc wfkxod xglype yhmzqf
zinarg ajobsh bkpcti clqduj dmrevk
ensfwl fotgxm gpuhyn hqvizo irwjap
jsxkbq ktylcr luzmds mvanet nwbofu
oxcpgv pydqhw qzerix rafsjy sbgtkz

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: tchula
Cipher: gxsfoz

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: tchula

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: tchula
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: tchula
Cipher: gpuhyn

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: tchula
Cipher: 443132541311

Extended Methods:
Method #1

Plaintext: tchula
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
t c h u l a 
4 3 3 5 1 1 
4 1 2 4 3 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: tchula
Cipher: oxadrc

Read more ...
Method #3

Plaintext: tchula
method variations:
olwdcq lwdcqo wdcqol
dcqolw cqolwd qolwdc

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: tchula

all 720 cipher variations:
tchula tchual tchlua tchlau tchalu tchaul tcuhla tcuhal tculha tculah tcualh
tcuahl tcluha tcluah tclhua tclhau tclahu tclauh tcaulh tcauhl tcaluh tcalhu
tcahlu tcahul thcula thcual thclua thclau thcalu thcaul thucla thucal thulca
thulac thualc thuacl thluca thluac thlcua thlcau thlacu thlauc thaulc thaucl
thaluc thalcu thaclu thacul tuhcla tuhcal tuhlca tuhlac tuhalc tuhacl tuchla
tuchal tuclha tuclah tucalh tucahl tulcha tulcah tulhca tulhac tulahc tulach
tuaclh tuachl tualch tualhc tuahlc tuahcl tlhuca tlhuac tlhcua tlhcau tlhacu
tlhauc tluhca tluhac tlucha tlucah tluach tluahc tlcuha tlcuah tlchua tlchau
tlcahu tlcauh tlauch tlauhc tlacuh tlachu tlahcu tlahuc tahulc tahucl tahluc
tahlcu tahclu tahcul tauhlc tauhcl taulhc taulch tauclh tauchl taluhc taluch
talhuc talhcu talchu talcuh taculh tacuhl tacluh taclhu tachlu tachul cthula
cthual cthlua cthlau cthalu cthaul ctuhla ctuhal ctulha ctulah ctualh ctuahl
ctluha ctluah ctlhua ctlhau ctlahu ctlauh ctaulh ctauhl ctaluh ctalhu ctahlu
ctahul chtula chtual chtlua chtlau chtalu chtaul chutla chutal chulta chulat
chualt chuatl chluta chluat chltua chltau chlatu chlaut chault chautl chalut
chaltu chatlu chatul cuhtla cuhtal cuhlta cuhlat cuhalt cuhatl cuthla cuthal
cutlha cutlah cutalh cutahl cultha cultah culhta culhat culaht culath cuatlh
cuathl cualth cualht cuahlt cuahtl clhuta clhuat clhtua clhtau clhatu clhaut
cluhta cluhat clutha clutah cluath cluaht cltuha cltuah clthua clthau cltahu
cltauh clauth clauht clatuh clathu clahtu clahut cahult cahutl cahlut cahltu
cahtlu cahtul cauhlt cauhtl caulht caulth cautlh cauthl caluht caluth calhut
calhtu calthu caltuh catulh catuhl catluh catlhu cathlu cathul hctula hctual
hctlua hctlau hctalu hctaul hcutla hcutal hculta hculat hcualt hcuatl hcluta
hcluat hcltua hcltau hclatu hclaut hcault hcautl hcalut hcaltu hcatlu hcatul
htcula htcual htclua htclau htcalu htcaul htucla htucal htulca htulac htualc
htuacl htluca htluac htlcua htlcau htlacu htlauc htaulc htaucl htaluc htalcu
htaclu htacul hutcla hutcal hutlca hutlac hutalc hutacl huctla huctal huclta
huclat hucalt hucatl hulcta hulcat hultca hultac hulatc hulact huaclt huactl
hualct hualtc huatlc huatcl hltuca hltuac hltcua hltcau hltacu hltauc hlutca
hlutac hlucta hlucat hluact hluatc hlcuta hlcuat hlctua hlctau hlcatu hlcaut
hlauct hlautc hlacut hlactu hlatcu hlatuc hatulc hatucl hatluc hatlcu hatclu
hatcul hautlc hautcl haultc haulct hauclt hauctl halutc haluct haltuc haltcu
halctu halcut hacult hacutl haclut hacltu hactlu hactul uchtla uchtal uchlta
uchlat uchalt uchatl ucthla ucthal uctlha uctlah uctalh uctahl ucltha ucltah
uclhta uclhat uclaht uclath ucatlh ucathl ucalth ucalht ucahlt ucahtl uhctla
uhctal uhclta uhclat uhcalt uhcatl uhtcla uhtcal uhtlca uhtlac uhtalc uhtacl
uhltca uhltac uhlcta uhlcat uhlact uhlatc uhatlc uhatcl uhaltc uhalct uhaclt
uhactl uthcla uthcal uthlca uthlac uthalc uthacl utchla utchal utclha utclah
utcalh utcahl utlcha utlcah utlhca utlhac utlahc utlach utaclh utachl utalch
utalhc utahlc utahcl ulhtca ulhtac ulhcta ulhcat ulhact ulhatc ulthca ulthac
ultcha ultcah ultach ultahc ulctha ulctah ulchta ulchat ulcaht ulcath ulatch
ulathc ulacth ulacht ulahct ulahtc uahtlc uahtcl uahltc uahlct uahclt uahctl
uathlc uathcl uatlhc uatlch uatclh uatchl ualthc ualtch ualhtc ualhct ualcht
ualcth uactlh uacthl uaclth uaclht uachlt uachtl lchuta lchuat lchtua lchtau
lchatu lchaut lcuhta lcuhat lcutha lcutah lcuath lcuaht lctuha lctuah lcthua
lcthau lctahu lctauh lcauth lcauht lcatuh lcathu lcahtu lcahut lhcuta lhcuat
lhctua lhctau lhcatu lhcaut lhucta lhucat lhutca lhutac lhuatc lhuact lhtuca
lhtuac lhtcua lhtcau lhtacu lhtauc lhautc lhauct lhatuc lhatcu lhactu lhacut
luhcta luhcat luhtca luhtac luhatc luhact luchta luchat luctha luctah lucath
lucaht lutcha lutcah luthca luthac lutahc lutach luacth luacht luatch luathc
luahtc luahct lthuca lthuac lthcua lthcau lthacu lthauc ltuhca ltuhac ltucha
ltucah ltuach ltuahc ltcuha ltcuah ltchua ltchau ltcahu ltcauh ltauch ltauhc
ltacuh ltachu ltahcu ltahuc lahutc lahuct lahtuc lahtcu lahctu lahcut lauhtc
lauhct lauthc lautch laucth laucht latuhc latuch lathuc lathcu latchu latcuh
lacuth lacuht lactuh lacthu lachtu lachut achult achutl achlut achltu achtlu
achtul acuhlt acuhtl aculht aculth acutlh acuthl acluht acluth aclhut aclhtu
aclthu acltuh actulh actuhl actluh actlhu acthlu acthul ahcult ahcutl ahclut
ahcltu ahctlu ahctul ahuclt ahuctl ahulct ahultc ahutlc ahutcl ahluct ahlutc
ahlcut ahlctu ahltcu ahltuc ahtulc ahtucl ahtluc ahtlcu ahtclu ahtcul auhclt
auhctl auhlct auhltc auhtlc auhtcl auchlt auchtl auclht auclth auctlh aucthl
aulcht aulcth aulhct aulhtc aulthc aultch autclh autchl autlch autlhc authlc
authcl alhuct alhutc alhcut alhctu alhtcu alhtuc aluhct aluhtc alucht alucth
alutch aluthc alcuht alcuth alchut alchtu alcthu alctuh altuch altuhc altcuh
altchu althcu althuc athulc athucl athluc athlcu athclu athcul atuhlc atuhcl
atulhc atulch atuclh atuchl atluhc atluch atlhuc atlhcu atlchu atlcuh atculh
atcuhl atcluh atclhu atchlu atchul

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

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