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: choris
cipher variations:
dipsjt ejqtku fkrulv glsvmw hmtwnx
inuxoy jovypz kpwzqa lqxarb mrybsc
nszctd otadue pubevf qvcfwg rwdgxh
sxehyi tyfizj uzgjak vahkbl wbilcm
xcjmdn ydkneo zelofp afmpgq bgnqhr

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: choris
Cipher: xslirh

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: choris

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: choris
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: choris
Cipher: pubevf

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: choris
Cipher: 313243244234

Extended Methods:
Method #1

Plaintext: choris
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
c h o r i s 
3 3 4 2 4 3 
1 2 3 4 2 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: choris
Cipher: niofsr

Read more ...
Method #3

Plaintext: choris
method variations:
lrhtmo rhtmol htmolr
tmolrh molrht olrhtm

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: choris

all 720 cipher variations:
choris chorsi choirs choisr chosir chosri chrois chrosi chrios chriso chrsio
chrsoi chiros chirso chiors chiosr chisor chisro chsrio chsroi chsiro chsior
chsoir chsori cohris cohrsi cohirs cohisr cohsir cohsri corhis corhsi corihs
corish corsih corshi coirhs coirsh coihrs coihsr coishr coisrh cosrih cosrhi
cosirh cosihr coshir coshri crohis crohsi croihs croish crosih croshi crhois
crhosi crhios crhiso crhsio crhsoi crihos crihso criohs criosh crisoh crisho
crshio crshoi crsiho crsioh crsoih crsohi ciorhs ciorsh ciohrs ciohsr cioshr
ciosrh cirohs cirosh cirhos cirhso cirsho cirsoh cihros cihrso cihors cihosr
cihsor cihsro cisrho cisroh cishro cishor cisohr cisorh csorih csorhi csoirh
csoihr csohir csohri csroih csrohi csrioh csriho csrhio csrhoi csiroh csirho
csiorh csiohr csihor csihro cshrio cshroi cshiro cshior cshoir cshori hcoris
hcorsi hcoirs hcoisr hcosir hcosri hcrois hcrosi hcrios hcriso hcrsio hcrsoi
hciros hcirso hciors hciosr hcisor hcisro hcsrio hcsroi hcsiro hcsior hcsoir
hcsori hocris hocrsi hocirs hocisr hocsir hocsri horcis horcsi horics horisc
horsic horsci hoircs hoirsc hoicrs hoicsr hoiscr hoisrc hosric hosrci hosirc
hosicr hoscir hoscri hrocis hrocsi hroics hroisc hrosic hrosci hrcois hrcosi
hrcios hrciso hrcsio hrcsoi hricos hricso hriocs hriosc hrisoc hrisco hrscio
hrscoi hrsico hrsioc hrsoic hrsoci hiorcs hiorsc hiocrs hiocsr hioscr hiosrc
hirocs hirosc hircos hircso hirsco hirsoc hicros hicrso hicors hicosr hicsor
hicsro hisrco hisroc hiscro hiscor hisocr hisorc hsoric hsorci hsoirc hsoicr
hsocir hsocri hsroic hsroci hsrioc hsrico hsrcio hsrcoi hsiroc hsirco hsiorc
hsiocr hsicor hsicro hscrio hscroi hsciro hscior hscoir hscori ohcris ohcrsi
ohcirs ohcisr ohcsir ohcsri ohrcis ohrcsi ohrics ohrisc ohrsic ohrsci ohircs
ohirsc ohicrs ohicsr ohiscr ohisrc ohsric ohsrci ohsirc ohsicr ohscir ohscri
ochris ochrsi ochirs ochisr ochsir ochsri ocrhis ocrhsi ocrihs ocrish ocrsih
ocrshi ocirhs ocirsh ocihrs ocihsr ocishr ocisrh ocsrih ocsrhi ocsirh ocsihr
ocshir ocshri orchis orchsi orcihs orcish orcsih orcshi orhcis orhcsi orhics
orhisc orhsic orhsci orihcs orihsc orichs oricsh orisch orishc orshic orshci
orsihc orsich orscih orschi oicrhs oicrsh oichrs oichsr oicshr oicsrh oirchs
oircsh oirhcs oirhsc oirshc oirsch oihrcs oihrsc oihcrs oihcsr oihscr oihsrc
oisrhc oisrch oishrc oishcr oischr oiscrh oscrih oscrhi oscirh oscihr oschir
oschri osrcih osrchi osrich osrihc osrhic osrhci osirch osirhc osicrh osichr
osihcr osihrc oshric oshrci oshirc oshicr oshcir oshcri rhocis rhocsi rhoics
rhoisc rhosic rhosci rhcois rhcosi rhcios rhciso rhcsio rhcsoi rhicos rhicso
rhiocs rhiosc rhisoc rhisco rhscio rhscoi rhsico rhsioc rhsoic rhsoci rohcis
rohcsi rohics rohisc rohsic rohsci rochis rochsi rocihs rocish rocsih rocshi
roichs roicsh roihcs roihsc roishc roisch roscih roschi rosich rosihc roshic
roshci rcohis rcohsi rcoihs rcoish rcosih rcoshi rchois rchosi rchios rchiso
rchsio rchsoi rcihos rcihso rciohs rciosh rcisoh rcisho rcshio rcshoi rcsiho
rcsioh rcsoih rcsohi riochs riocsh riohcs riohsc rioshc riosch ricohs ricosh
richos richso ricsho ricsoh rihcos rihcso rihocs rihosc rihsoc rihsco rischo
riscoh rishco rishoc risohc risoch rsocih rsochi rsoich rsoihc rsohic rsohci
rscoih rscohi rscioh rsciho rschio rschoi rsicoh rsicho rsioch rsiohc rsihoc
rsihco rshcio rshcoi rshico rshioc rshoic rshoci ihorcs ihorsc ihocrs ihocsr
ihoscr ihosrc ihrocs ihrosc ihrcos ihrcso ihrsco ihrsoc ihcros ihcrso ihcors
ihcosr ihcsor ihcsro ihsrco ihsroc ihscro ihscor ihsocr ihsorc iohrcs iohrsc
iohcrs iohcsr iohscr iohsrc iorhcs iorhsc iorchs iorcsh iorsch iorshc iocrhs
iocrsh iochrs iochsr iocshr iocsrh iosrch iosrhc ioscrh ioschr ioshcr ioshrc
irohcs irohsc irochs irocsh irosch iroshc irhocs irhosc irhcos irhcso irhsco
irhsoc irchos irchso ircohs ircosh ircsoh ircsho irshco irshoc irscho irscoh
irsoch irsohc icorhs icorsh icohrs icohsr icoshr icosrh icrohs icrosh icrhos
icrhso icrsho icrsoh ichros ichrso ichors ichosr ichsor ichsro icsrho icsroh
icshro icshor icsohr icsorh isorch isorhc isocrh isochr isohcr isohrc isroch
isrohc isrcoh isrcho isrhco isrhoc iscroh iscrho iscorh iscohr ischor ischro
ishrco ishroc ishcro ishcor ishocr ishorc shoric shorci shoirc shoicr shocir
shocri shroic shroci shrioc shrico shrcio shrcoi shiroc shirco shiorc shiocr
shicor shicro shcrio shcroi shciro shcior shcoir shcori sohric sohrci sohirc
sohicr sohcir sohcri sorhic sorhci sorihc sorich sorcih sorchi soirhc soirch
soihrc soihcr soichr soicrh socrih socrhi socirh socihr sochir sochri srohic
srohci sroihc sroich srocih srochi srhoic srhoci srhioc srhico srhcio srhcoi
srihoc srihco sriohc srioch sricoh sricho srchio srchoi srciho srcioh srcoih
srcohi siorhc siorch siohrc siohcr siochr siocrh sirohc siroch sirhoc sirhco
sircho sircoh sihroc sihrco sihorc sihocr sihcor sihcro sicrho sicroh sichro
sichor sicohr sicorh scorih scorhi scoirh scoihr scohir scohri scroih scrohi
scrioh scriho scrhio scrhoi sciroh scirho sciorh sciohr scihor scihro schrio
schroi schiro schior schoir schori

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

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