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: mucoid
cipher variations:
nvdpje oweqkf pxfrlg qygsmh rzhtni
saiuoj tbjvpk uckwql vdlxrm wemysn
xfnzto ygoaup zhpbvq aiqcwr bjrdxs
ckseyt dltfzu emugav fnvhbw gowicx
hpxjdy iqykez jrzlfa ksamgb ltbnhc

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: mucoid
Cipher: nfxlrw

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: mucoid

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: mucoid
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: mucoid
Cipher: zhpbvq

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: mucoid
Cipher: 235431434241

Extended Methods:
Method #1

Plaintext: mucoid
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
m u c o i d 
2 5 3 4 4 4 
3 4 1 3 2 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: mucoid
Cipher: wstslb

Read more ...
Method #3

Plaintext: mucoid
method variations:
xoqsrf oqsrfx qsrfxo
srfxoq rfxoqs fxoqsr

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: mucoid

all 720 cipher variations:
mucoid mucodi muciod mucido mucdio mucdoi muocid muocdi muoicd muoidc muodic
muodci muiocd muiodc muicod muicdo muidco muidoc mudoic mudoci mudioc mudico
mudcio mudcoi mcuoid mcuodi mcuiod mcuido mcudio mcudoi mcouid mcoudi mcoiud
mcoidu mcodiu mcodui mcioud mciodu mciuod mciudo mciduo mcidou mcdoiu mcdoui
mcdiou mcdiuo mcduio mcduoi mocuid mocudi mociud mocidu mocdiu mocdui moucid
moucdi mouicd mouidc moudic moudci moiucd moiudc moicud moicdu moidcu moiduc
moduic moduci modiuc modicu modciu modcui micoud micodu micuod micudo micduo
micdou miocud miocdu mioucd mioudc mioduc miodcu miuocd miuodc miucod miucdo
miudco miudoc midouc midocu miduoc miduco midcuo midcou mdcoiu mdcoui mdciou
mdciuo mdcuio mdcuoi mdociu mdocui mdoicu mdoiuc mdouic mdouci mdiocu mdiouc
mdicou mdicuo mdiuco mdiuoc mduoic mduoci mduioc mduico mducio mducoi umcoid
umcodi umciod umcido umcdio umcdoi umocid umocdi umoicd umoidc umodic umodci
umiocd umiodc umicod umicdo umidco umidoc umdoic umdoci umdioc umdico umdcio
umdcoi ucmoid ucmodi ucmiod ucmido ucmdio ucmdoi ucomid ucomdi ucoimd ucoidm
ucodim ucodmi uciomd uciodm ucimod ucimdo ucidmo ucidom ucdoim ucdomi ucdiom
ucdimo ucdmio ucdmoi uocmid uocmdi uocimd uocidm uocdim uocdmi uomcid uomcdi
uomicd uomidc uomdic uomdci uoimcd uoimdc uoicmd uoicdm uoidcm uoidmc uodmic
uodmci uodimc uodicm uodcim uodcmi uicomd uicodm uicmod uicmdo uicdmo uicdom
uiocmd uiocdm uiomcd uiomdc uiodmc uiodcm uimocd uimodc uimcod uimcdo uimdco
uimdoc uidomc uidocm uidmoc uidmco uidcmo uidcom udcoim udcomi udciom udcimo
udcmio udcmoi udocim udocmi udoicm udoimc udomic udomci udiocm udiomc udicom
udicmo udimco udimoc udmoic udmoci udmioc udmico udmcio udmcoi cumoid cumodi
cumiod cumido cumdio cumdoi cuomid cuomdi cuoimd cuoidm cuodim cuodmi cuiomd
cuiodm cuimod cuimdo cuidmo cuidom cudoim cudomi cudiom cudimo cudmio cudmoi
cmuoid cmuodi cmuiod cmuido cmudio cmudoi cmouid cmoudi cmoiud cmoidu cmodiu
cmodui cmioud cmiodu cmiuod cmiudo cmiduo cmidou cmdoiu cmdoui cmdiou cmdiuo
cmduio cmduoi comuid comudi comiud comidu comdiu comdui coumid coumdi couimd
couidm coudim coudmi coiumd coiudm coimud coimdu coidmu coidum coduim codumi
codium codimu codmiu codmui cimoud cimodu cimuod cimudo cimduo cimdou ciomud
ciomdu cioumd cioudm ciodum ciodmu ciuomd ciuodm ciumod ciumdo ciudmo ciudom
cidoum cidomu ciduom cidumo cidmuo cidmou cdmoiu cdmoui cdmiou cdmiuo cdmuio
cdmuoi cdomiu cdomui cdoimu cdoium cdouim cdoumi cdiomu cdioum cdimou cdimuo
cdiumo cdiuom cduoim cduomi cduiom cduimo cdumio cdumoi oucmid oucmdi oucimd
oucidm oucdim oucdmi oumcid oumcdi oumicd oumidc oumdic oumdci ouimcd ouimdc
ouicmd ouicdm ouidcm ouidmc oudmic oudmci oudimc oudicm oudcim oudcmi ocumid
ocumdi ocuimd ocuidm ocudim ocudmi ocmuid ocmudi ocmiud ocmidu ocmdiu ocmdui
ocimud ocimdu ociumd ociudm ocidum ocidmu ocdmiu ocdmui ocdimu ocdium ocduim
ocdumi omcuid omcudi omciud omcidu omcdiu omcdui omucid omucdi omuicd omuidc
omudic omudci omiucd omiudc omicud omicdu omidcu omiduc omduic omduci omdiuc
omdicu omdciu omdcui oicmud oicmdu oicumd oicudm oicdum oicdmu oimcud oimcdu
oimucd oimudc oimduc oimdcu oiumcd oiumdc oiucmd oiucdm oiudcm oiudmc oidmuc
oidmcu oidumc oiducm oidcum oidcmu odcmiu odcmui odcimu odcium odcuim odcumi
odmciu odmcui odmicu odmiuc odmuic odmuci odimcu odimuc odicmu odicum odiucm
odiumc odumic odumci oduimc oduicm oducim oducmi iucomd iucodm iucmod iucmdo
iucdmo iucdom iuocmd iuocdm iuomcd iuomdc iuodmc iuodcm iumocd iumodc iumcod
iumcdo iumdco iumdoc iudomc iudocm iudmoc iudmco iudcmo iudcom icuomd icuodm
icumod icumdo icudmo icudom icoumd icoudm icomud icomdu icodmu icodum icmoud
icmodu icmuod icmudo icmduo icmdou icdomu icdoum icdmou icdmuo icdumo icduom
iocumd iocudm iocmud iocmdu iocdmu iocdum ioucmd ioucdm ioumcd ioumdc ioudmc
ioudcm iomucd iomudc iomcud iomcdu iomdcu iomduc iodumc ioducm iodmuc iodmcu
iodcmu iodcum imcoud imcodu imcuod imcudo imcduo imcdou imocud imocdu imoucd
imoudc imoduc imodcu imuocd imuodc imucod imucdo imudco imudoc imdouc imdocu
imduoc imduco imdcuo imdcou idcomu idcoum idcmou idcmuo idcumo idcuom idocmu
idocum idomcu idomuc idoumc idoucm idmocu idmouc idmcou idmcuo idmuco idmuoc
iduomc iduocm idumoc idumco iducmo iducom ducoim ducomi duciom ducimo ducmio
ducmoi duocim duocmi duoicm duoimc duomic duomci duiocm duiomc duicom duicmo
duimco duimoc dumoic dumoci dumioc dumico dumcio dumcoi dcuoim dcuomi dcuiom
dcuimo dcumio dcumoi dcouim dcoumi dcoium dcoimu dcomiu dcomui dcioum dciomu
dciuom dciumo dcimuo dcimou dcmoiu dcmoui dcmiou dcmiuo dcmuio dcmuoi docuim
documi docium docimu docmiu docmui doucim doucmi douicm douimc doumic doumci
doiucm doiumc doicum doicmu doimcu doimuc domuic domuci domiuc domicu domciu
domcui dicoum dicomu dicuom dicumo dicmuo dicmou diocum diocmu dioucm dioumc
diomuc diomcu diuocm diuomc diucom diucmo diumco diumoc dimouc dimocu dimuoc
dimuco dimcuo dimcou dmcoiu dmcoui dmciou dmciuo dmcuio dmcuoi dmociu dmocui
dmoicu dmoiuc dmouic dmouci dmiocu dmiouc dmicou dmicuo dmiuco dmiuoc dmuoic
dmuoci dmuioc dmuico dmucio dmucoi

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

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