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: exarmo
cipher variations:
fybsnp gzctoq hadupr ibevqs jcfwrt
kdgxsu lehytv mfizuw ngjavx ohkbwy
pilcxz qjmdya rknezb slofac tmpgbd
unqhce voridf wpsjeg xqtkfh yrulgi
zsvmhj atwnik buxojl cvypkm dwzqln

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: exarmo
Cipher: vczinl

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: exarmo

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: exarmo
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: exarmo
Cipher: rknezb

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: exarmo
Cipher: 513511242343

Extended Methods:
Method #1

Plaintext: exarmo
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
e x a r m o 
5 3 1 2 2 4 
1 5 1 4 3 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: exarmo
Cipher: pfrvqn

Read more ...
Method #3

Plaintext: exarmo
method variations:
lefisx efisxl fisxle
isxlef sxlefi xlefis

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: exarmo

all 720 cipher variations:
exarmo exarom examro examor exaomr exaorm exramo exraom exrmao exrmoa exroma
exroam exmrao exmroa exmaro exmaor exmoar exmora exorma exoram exomra exomar
exoamr exoarm eaxrmo eaxrom eaxmro eaxmor eaxomr eaxorm earxmo earxom earmxo
earmox earomx earoxm eamrxo eamrox eamxro eamxor eamoxr eamorx eaormx eaorxm
eaomrx eaomxr eaoxmr eaoxrm eraxmo eraxom eramxo eramox eraomx eraoxm erxamo
erxaom erxmao erxmoa erxoma erxoam ermxao ermxoa ermaxo ermaox ermoax ermoxa
eroxma eroxam eromxa eromax eroamx eroaxm emarxo emarox emaxro emaxor emaoxr
emaorx emraxo emraox emrxao emrxoa emroxa emroax emxrao emxroa emxaro emxaor
emxoar emxora emorxa emorax emoxra emoxar emoaxr emoarx eoarmx eoarxm eoamrx
eoamxr eoaxmr eoaxrm eoramx eoraxm eormax eormxa eorxma eorxam eomrax eomrxa
eomarx eomaxr eomxar eomxra eoxrma eoxram eoxmra eoxmar eoxamr eoxarm xearmo
xearom xeamro xeamor xeaomr xeaorm xeramo xeraom xermao xermoa xeroma xeroam
xemrao xemroa xemaro xemaor xemoar xemora xeorma xeoram xeomra xeomar xeoamr
xeoarm xaermo xaerom xaemro xaemor xaeomr xaeorm xaremo xareom xarmeo xarmoe
xarome xaroem xamreo xamroe xamero xameor xamoer xamore xaorme xaorem xaomre
xaomer xaoemr xaoerm xraemo xraeom xrameo xramoe xraome xraoem xreamo xreaom
xremao xremoa xreoma xreoam xrmeao xrmeoa xrmaeo xrmaoe xrmoae xrmoea xroema
xroeam xromea xromae xroame xroaem xmareo xmaroe xmaero xmaeor xmaoer xmaore
xmraeo xmraoe xmreao xmreoa xmroea xmroae xmerao xmeroa xmearo xmeaor xmeoar
xmeora xmorea xmorae xmoera xmoear xmoaer xmoare xoarme xoarem xoamre xoamer
xoaemr xoaerm xorame xoraem xormae xormea xorema xoream xomrae xomrea xomare
xomaer xomear xomera xoerma xoeram xoemra xoemar xoeamr xoearm axermo axerom
axemro axemor axeomr axeorm axremo axreom axrmeo axrmoe axrome axroem axmreo
axmroe axmero axmeor axmoer axmore axorme axorem axomre axomer axoemr axoerm
aexrmo aexrom aexmro aexmor aexomr aexorm aerxmo aerxom aermxo aermox aeromx
aeroxm aemrxo aemrox aemxro aemxor aemoxr aemorx aeormx aeorxm aeomrx aeomxr
aeoxmr aeoxrm arexmo arexom aremxo aremox areomx areoxm arxemo arxeom arxmeo
arxmoe arxome arxoem armxeo armxoe armexo armeox armoex armoxe aroxme aroxem
aromxe aromex aroemx aroexm amerxo amerox amexro amexor ameoxr ameorx amrexo
amreox amrxeo amrxoe amroxe amroex amxreo amxroe amxero amxeor amxoer amxore
amorxe amorex amoxre amoxer amoexr amoerx aoermx aoerxm aoemrx aoemxr aoexmr
aoexrm aoremx aorexm aormex aormxe aorxme aorxem aomrex aomrxe aomerx aomexr
aomxer aomxre aoxrme aoxrem aoxmre aoxmer aoxemr aoxerm rxaemo rxaeom rxameo
rxamoe rxaome rxaoem rxeamo rxeaom rxemao rxemoa rxeoma rxeoam rxmeao rxmeoa
rxmaeo rxmaoe rxmoae rxmoea rxoema rxoeam rxomea rxomae rxoame rxoaem raxemo
raxeom raxmeo raxmoe raxome raxoem raexmo raexom raemxo raemox raeomx raeoxm
ramexo rameox ramxeo ramxoe ramoxe ramoex raoemx raoexm raomex raomxe raoxme
raoxem reaxmo reaxom reamxo reamox reaomx reaoxm rexamo rexaom rexmao rexmoa
rexoma rexoam remxao remxoa remaxo remaox remoax remoxa reoxma reoxam reomxa
reomax reoamx reoaxm rmaexo rmaeox rmaxeo rmaxoe rmaoxe rmaoex rmeaxo rmeaox
rmexao rmexoa rmeoxa rmeoax rmxeao rmxeoa rmxaeo rmxaoe rmxoae rmxoea rmoexa
rmoeax rmoxea rmoxae rmoaxe rmoaex roaemx roaexm roamex roamxe roaxme roaxem
roeamx roeaxm roemax roemxa roexma roexam romeax romexa romaex romaxe romxae
romxea roxema roxeam roxmea roxmae roxame roxaem mxareo mxaroe mxaero mxaeor
mxaoer mxaore mxraeo mxraoe mxreao mxreoa mxroea mxroae mxerao mxeroa mxearo
mxeaor mxeoar mxeora mxorea mxorae mxoera mxoear mxoaer mxoare maxreo maxroe
maxero maxeor maxoer maxore marxeo marxoe marexo mareox maroex maroxe maerxo
maerox maexro maexor maeoxr maeorx maorex maorxe maoerx maoexr maoxer maoxre
mraxeo mraxoe mraexo mraeox mraoex mraoxe mrxaeo mrxaoe mrxeao mrxeoa mrxoea
mrxoae mrexao mrexoa mreaxo mreaox mreoax mreoxa mroxea mroxae mroexa mroeax
mroaex mroaxe mearxo mearox meaxro meaxor meaoxr meaorx meraxo meraox merxao
merxoa meroxa meroax mexrao mexroa mexaro mexaor mexoar mexora meorxa meorax
meoxra meoxar meoaxr meoarx moarex moarxe moaerx moaexr moaxer moaxre moraex
moraxe moreax morexa morxea morxae moerax moerxa moearx moeaxr moexar moexra
moxrea moxrae moxera moxear moxaer moxare oxarme oxarem oxamre oxamer oxaemr
oxaerm oxrame oxraem oxrmae oxrmea oxrema oxream oxmrae oxmrea oxmare oxmaer
oxmear oxmera oxerma oxeram oxemra oxemar oxeamr oxearm oaxrme oaxrem oaxmre
oaxmer oaxemr oaxerm oarxme oarxem oarmxe oarmex oaremx oarexm oamrxe oamrex
oamxre oamxer oamexr oamerx oaermx oaerxm oaemrx oaemxr oaexmr oaexrm oraxme
oraxem oramxe oramex oraemx oraexm orxame orxaem orxmae orxmea orxema orxeam
ormxae ormxea ormaxe ormaex ormeax ormexa orexma orexam oremxa oremax oreamx
oreaxm omarxe omarex omaxre omaxer omaexr omaerx omraxe omraex omrxae omrxea
omrexa omreax omxrae omxrea omxare omxaer omxear omxera omerxa omerax omexra
omexar omeaxr omearx oearmx oearxm oeamrx oeamxr oeaxmr oeaxrm oeramx oeraxm
oermax oermxa oerxma oerxam oemrax oemrxa oemarx oemaxr oemxar oemxra oexrma
oexram oexmra oexmar oexamr oexarm

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

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