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: huygen
cipher variations:
ivzhfo jwaigp kxbjhq lyckir mzdljs
naemkt obfnlu pcgomv qdhpnw reiqox
sfjrpy tgksqz uhltra vimusb wjnvtc
xkowud ylpxve zmqywf anrzxg bosayh
cptbzi dqucaj ervdbk fswecl gtxfdm

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: huygen
Cipher: sfbtvm

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: huygen

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: huygen
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: huygen
Cipher: uhltra

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: huygen
Cipher: 325445225133

Extended Methods:
Method #1

Plaintext: huygen
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
h u y g e n 
3 5 4 2 5 3 
2 4 5 2 1 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: huygen
Cipher: xiprkl

Read more ...
Method #3

Plaintext: huygen
method variations:
wtkwln tkwlnw kwlnwt
wlnwtk lnwtkw nwtkwl

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: huygen

all 720 cipher variations:
huygen huygne huyegn huyeng huyneg huynge hugyen hugyne hugeyn hugeny hugney
hugnye huegyn huegny hueygn hueyng huenyg huengy hungey hungye hunegy huneyg
hunyeg hunyge hyugen hyugne hyuegn hyueng hyuneg hyunge hyguen hygune hygeun
hygenu hygneu hygnue hyegun hyegnu hyeugn hyeung hyenug hyengu hyngeu hyngue
hynegu hyneug hynueg hynuge hgyuen hgyune hgyeun hgyenu hgyneu hgynue hguyen
hguyne hgueyn hgueny hguney hgunye hgeuyn hgeuny hgeyun hgeynu hgenyu hgenuy
hgnuey hgnuye hgneuy hgneyu hgnyeu hgnyue heygun heygnu heyugn heyung heynug
heyngu hegyun hegynu heguyn heguny hegnuy hegnyu heugyn heugny heuygn heuyng
heunyg heungy henguy hengyu henugy henuyg henyug henygu hnygeu hnygue hnyegu
hnyeug hnyueg hnyuge hngyeu hngyue hngeyu hngeuy hnguey hnguye hnegyu hneguy
hneygu hneyug hneuyg hneugy hnugey hnugye hnuegy hnueyg hnuyeg hnuyge uhygen
uhygne uhyegn uhyeng uhyneg uhynge uhgyen uhgyne uhgeyn uhgeny uhgney uhgnye
uhegyn uhegny uheygn uheyng uhenyg uhengy uhngey uhngye uhnegy uhneyg uhnyeg
uhnyge uyhgen uyhgne uyhegn uyheng uyhneg uyhnge uyghen uyghne uygehn uygenh
uygneh uygnhe uyeghn uyegnh uyehgn uyehng uyenhg uyengh uyngeh uynghe uynegh
uynehg uynheg uynhge ugyhen ugyhne ugyehn ugyenh ugyneh ugynhe ughyen ughyne
ugheyn ugheny ughney ughnye ugehyn ugehny ugeyhn ugeynh ugenyh ugenhy ugnhey
ugnhye ugnehy ugneyh ugnyeh ugnyhe ueyghn ueygnh ueyhgn ueyhng ueynhg ueyngh
uegyhn uegynh ueghyn ueghny uegnhy uegnyh uehgyn uehgny uehygn uehyng uehnyg
uehngy uenghy uengyh uenhgy uenhyg uenyhg uenygh unygeh unyghe unyegh unyehg
unyheg unyhge ungyeh ungyhe ungeyh ungehy unghey unghye unegyh uneghy uneygh
uneyhg unehyg unehgy unhgey unhgye unhegy unheyg unhyeg unhyge yuhgen yuhgne
yuhegn yuheng yuhneg yuhnge yughen yughne yugehn yugenh yugneh yugnhe yueghn
yuegnh yuehgn yuehng yuenhg yuengh yungeh yunghe yunegh yunehg yunheg yunhge
yhugen yhugne yhuegn yhueng yhuneg yhunge yhguen yhgune yhgeun yhgenu yhgneu
yhgnue yhegun yhegnu yheugn yheung yhenug yhengu yhngeu yhngue yhnegu yhneug
yhnueg yhnuge yghuen yghune ygheun yghenu yghneu yghnue yguhen yguhne yguehn
yguenh yguneh ygunhe ygeuhn ygeunh ygehun ygehnu ygenhu ygenuh ygnueh ygnuhe
ygneuh ygnehu ygnheu ygnhue yehgun yehgnu yehugn yehung yehnug yehngu yeghun
yeghnu yeguhn yegunh yegnuh yegnhu yeughn yeugnh yeuhgn yeuhng yeunhg yeungh
yenguh yenghu yenugh yenuhg yenhug yenhgu ynhgeu ynhgue ynhegu ynheug ynhueg
ynhuge yngheu ynghue yngehu yngeuh yngueh ynguhe yneghu yneguh ynehgu ynehug
yneuhg yneugh ynugeh ynughe ynuegh ynuehg ynuheg ynuhge guyhen guyhne guyehn
guyenh guyneh guynhe guhyen guhyne guheyn guheny guhney guhnye guehyn guehny
gueyhn gueynh guenyh guenhy gunhey gunhye gunehy guneyh gunyeh gunyhe gyuhen
gyuhne gyuehn gyuenh gyuneh gyunhe gyhuen gyhune gyheun gyhenu gyhneu gyhnue
gyehun gyehnu gyeuhn gyeunh gyenuh gyenhu gynheu gynhue gynehu gyneuh gynueh
gynuhe ghyuen ghyune ghyeun ghyenu ghyneu ghynue ghuyen ghuyne ghueyn ghueny
ghuney ghunye gheuyn gheuny gheyun gheynu ghenyu ghenuy ghnuey ghnuye ghneuy
ghneyu ghnyeu ghnyue geyhun geyhnu geyuhn geyunh geynuh geynhu gehyun gehynu
gehuyn gehuny gehnuy gehnyu geuhyn geuhny geuyhn geuynh geunyh geunhy genhuy
genhyu genuhy genuyh genyuh genyhu gnyheu gnyhue gnyehu gnyeuh gnyueh gnyuhe
gnhyeu gnhyue gnheyu gnheuy gnhuey gnhuye gnehyu gnehuy gneyhu gneyuh gneuyh
gneuhy gnuhey gnuhye gnuehy gnueyh gnuyeh gnuyhe euyghn euygnh euyhgn euyhng
euynhg euyngh eugyhn eugynh eughyn eughny eugnhy eugnyh euhgyn euhgny euhygn
euhyng euhnyg euhngy eunghy eungyh eunhgy eunhyg eunyhg eunygh eyughn eyugnh
eyuhgn eyuhng eyunhg eyungh eyguhn eygunh eyghun eyghnu eygnhu eygnuh eyhgun
eyhgnu eyhugn eyhung eyhnug eyhngu eynghu eynguh eynhgu eynhug eynuhg eynugh
egyuhn egyunh egyhun egyhnu egynhu egynuh eguyhn eguynh eguhyn eguhny egunhy
egunyh eghuyn eghuny eghyun eghynu eghnyu eghnuy egnuhy egnuyh egnhuy egnhyu
egnyhu egnyuh ehygun ehygnu ehyugn ehyung ehynug ehyngu ehgyun ehgynu ehguyn
ehguny ehgnuy ehgnyu ehugyn ehugny ehuygn ehuyng ehunyg ehungy ehnguy ehngyu
ehnugy ehnuyg ehnyug ehnygu enyghu enyguh enyhgu enyhug enyuhg enyugh engyhu
engyuh enghyu enghuy enguhy enguyh enhgyu enhguy enhygu enhyug enhuyg enhugy
enughy enugyh enuhgy enuhyg enuyhg enuygh nuygeh nuyghe nuyegh nuyehg nuyheg
nuyhge nugyeh nugyhe nugeyh nugehy nughey nughye nuegyh nueghy nueygh nueyhg
nuehyg nuehgy nuhgey nuhgye nuhegy nuheyg nuhyeg nuhyge nyugeh nyughe nyuegh
nyuehg nyuheg nyuhge nygueh nyguhe nygeuh nygehu nygheu nyghue nyeguh nyeghu
nyeugh nyeuhg nyehug nyehgu nyhgeu nyhgue nyhegu nyheug nyhueg nyhuge ngyueh
ngyuhe ngyeuh ngyehu ngyheu ngyhue nguyeh nguyhe ngueyh nguehy nguhey nguhye
ngeuyh ngeuhy ngeyuh ngeyhu ngehyu ngehuy nghuey nghuye ngheuy ngheyu nghyeu
nghyue neyguh neyghu neyugh neyuhg neyhug neyhgu negyuh negyhu neguyh neguhy
neghuy neghyu neugyh neughy neuygh neuyhg neuhyg neuhgy nehguy nehgyu nehugy
nehuyg nehyug nehygu nhygeu nhygue nhyegu nhyeug nhyueg nhyuge nhgyeu nhgyue
nhgeyu nhgeuy nhguey nhguye nhegyu nheguy nheygu nheyug nheuyg nheugy nhugey
nhugye nhuegy nhueyg nhuyeg nhuyge

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

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