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: cronin
cipher variations:
dspojo etqpkp furqlq gvsrmr hwtsns
ixutot jyvupu kzwvqv laxwrw mbyxsx
nczyty odazuz pebava qfcbwb rgdcxc
shedyd tifeze ujgfaf vkhgbg wlihch
xmjidi ynkjej zolkfk apmlgl bqnmhm

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: cronin
Cipher: xilmrm

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: cronin

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: cronin
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: cronin
Cipher: pebava

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: cronin
Cipher: 312443334233

Extended Methods:
Method #1

Plaintext: cronin
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
c r o n i n 
3 2 4 3 4 3 
1 4 3 3 2 3 
They are then read out in rows:
Then divided up into pairs again, and the pairs turned back into letters using the square:
Plain: cronin
Cipher: hooqnm

Read more ...
Method #3

Plaintext: cronin
method variations:
ftnsmn tnsmnf nsmnft
smnftn mnftns nftnsm

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: cronin

all 720 cipher variations:
cronin cronni croinn croinn cronin cronni crnoin crnoni crnion crnino crnnio
crnnoi crinon crinno crionn crionn crinon crinno crnnio crnnoi crnino crnion
crnoin crnoni cornin cornni corinn corinn cornin cornni conrin conrni conirn
coninr connir connri coinrn coinnr coirnn coirnn coinrn coinnr connir connri
coninr conirn conrin conrni cnorin cnorni cnoirn cnoinr cnonir cnonri cnroin
cnroni cnrion cnrino cnrnio cnrnoi cniron cnirno cniorn cnionr cninor cninro
cnnrio cnnroi cnniro cnnior cnnoir cnnori cionrn cionnr ciornn ciornn cionrn
cionnr cinorn cinonr cinron cinrno cinnro cinnor cirnon cirnno cironn cironn
cirnon cirnno cinnro cinnor cinrno cinron cinorn cinonr cnonir cnonri cnoinr
cnoirn cnorin cnorni cnnoir cnnori cnnior cnniro cnnrio cnnroi cninor cninro
cnionr cniorn cniron cnirno cnrnio cnrnoi cnrino cnrion cnroin cnroni rconin
rconni rcoinn rcoinn rconin rconni rcnoin rcnoni rcnion rcnino rcnnio rcnnoi
rcinon rcinno rcionn rcionn rcinon rcinno rcnnio rcnnoi rcnino rcnion rcnoin
rcnoni rocnin rocnni rocinn rocinn rocnin rocnni roncin roncni ronicn roninc
ronnic ronnci roincn roinnc roicnn roicnn roincn roinnc ronnic ronnci roninc
ronicn roncin roncni rnocin rnocni rnoicn rnoinc rnonic rnonci rncoin rnconi
rncion rncino rncnio rncnoi rnicon rnicno rniocn rnionc rninoc rninco rnncio
rnncoi rnnico rnnioc rnnoic rnnoci rioncn rionnc riocnn riocnn rioncn rionnc
rinocn rinonc rincon rincno rinnco rinnoc ricnon ricnno riconn riconn ricnon
ricnno rinnco rinnoc rincno rincon rinocn rinonc rnonic rnonci rnoinc rnoicn
rnocin rnocni rnnoic rnnoci rnnioc rnnico rnncio rnncoi rninoc rninco rnionc
rniocn rnicon rnicno rncnio rncnoi rncino rncion rncoin rnconi orcnin orcnni
orcinn orcinn orcnin orcnni orncin orncni ornicn orninc ornnic ornnci orincn
orinnc oricnn oricnn orincn orinnc ornnic ornnci orninc ornicn orncin orncni
ocrnin ocrnni ocrinn ocrinn ocrnin ocrnni ocnrin ocnrni ocnirn ocninr ocnnir
ocnnri ocinrn ocinnr ocirnn ocirnn ocinrn ocinnr ocnnir ocnnri ocninr ocnirn
ocnrin ocnrni oncrin oncrni oncirn oncinr oncnir oncnri onrcin onrcni onricn
onrinc onrnic onrnci onircn onirnc onicrn onicnr onincr oninrc onnric onnrci
onnirc onnicr onncir onncri oicnrn oicnnr oicrnn oicrnn oicnrn oicnnr oincrn
oincnr oinrcn oinrnc oinnrc oinncr oirncn oirnnc oircnn oircnn oirncn oirnnc
oinnrc oinncr oinrnc oinrcn oincrn oincnr oncnir oncnri oncinr oncirn oncrin
oncrni onncir onncri onnicr onnirc onnric onnrci onincr oninrc onicnr onicrn
onircn onirnc onrnic onrnci onrinc onricn onrcin onrcni nrocin nrocni nroicn
nroinc nronic nronci nrcoin nrconi nrcion nrcino nrcnio nrcnoi nricon nricno
nriocn nrionc nrinoc nrinco nrncio nrncoi nrnico nrnioc nrnoic nrnoci norcin
norcni noricn norinc nornic nornci nocrin nocrni nocirn nocinr nocnir nocnri
noicrn noicnr noircn noirnc noinrc noincr noncir noncri nonicr nonirc nonric
nonrci ncorin ncorni ncoirn ncoinr nconir nconri ncroin ncroni ncrion ncrino
ncrnio ncrnoi nciron ncirno nciorn ncionr ncinor ncinro ncnrio ncnroi ncniro
ncnior ncnoir ncnori niocrn niocnr niorcn niornc nionrc nioncr nicorn niconr
nicron nicrno nicnro nicnor nircon nircno nirocn nironc nirnoc nirnco nincro
nincor ninrco ninroc ninorc ninocr nnocir nnocri nnoicr nnoirc nnoric nnorci
nncoir nncori nncior nnciro nncrio nncroi nnicor nnicro nniocr nniorc nniroc
nnirco nnrcio nnrcoi nnrico nnrioc nnroic nnroci ironcn ironnc irocnn irocnn
ironcn ironnc irnocn irnonc irncon irncno irnnco irnnoc ircnon ircnno irconn
irconn ircnon ircnno irnnco irnnoc irncno irncon irnocn irnonc iorncn iornnc
iorcnn iorcnn iorncn iornnc ionrcn ionrnc ioncrn ioncnr ionncr ionnrc iocnrn
iocnnr iocrnn iocrnn iocnrn iocnnr ionncr ionnrc ioncnr ioncrn ionrcn ionrnc
inorcn inornc inocrn inocnr inoncr inonrc inrocn inronc inrcon inrcno inrnco
inrnoc incron incrno incorn inconr incnor incnro innrco innroc inncro inncor
innocr innorc iconrn iconnr icornn icornn iconrn iconnr icnorn icnonr icnron
icnrno icnnro icnnor icrnon icrnno icronn icronn icrnon icrnno icnnro icnnor
icnrno icnron icnorn icnonr inoncr inonrc inocnr inocrn inorcn inornc innocr
innorc inncor inncro innrco innroc incnor incnro inconr incorn incron incrno
inrnco inrnoc inrcno inrcon inrocn inronc nronic nronci nroinc nroicn nrocin
nrocni nrnoic nrnoci nrnioc nrnico nrncio nrncoi nrinoc nrinco nrionc nriocn
nricon nricno nrcnio nrcnoi nrcino nrcion nrcoin nrconi nornic nornci norinc
noricn norcin norcni nonric nonrci nonirc nonicr noncir noncri noinrc noincr
noirnc noircn noicrn noicnr nocnir nocnri nocinr nocirn nocrin nocrni nnoric
nnorci nnoirc nnoicr nnocir nnocri nnroic nnroci nnrioc nnrico nnrcio nnrcoi
nniroc nnirco nniorc nniocr nnicor nnicro nncrio nncroi nnciro nncior nncoir
nncori nionrc nioncr niornc niorcn niocrn niocnr ninorc ninocr ninroc ninrco
nincro nincor nirnoc nirnco nironc nirocn nircon nircno nicnro nicnor nicrno
nicron nicorn niconr nconir nconri ncoinr ncoirn ncorin ncorni ncnoir ncnori
ncnior ncniro ncnrio ncnroi ncinor ncinro ncionr nciorn nciron ncirno ncrnio
ncrnoi ncrino ncrion ncroin ncroni

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

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