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: frison
cipher variations:
gsjtpo htkuqp iulvrq jvmwsr kwnxts
lxoyut mypzvu nzqawv oarbxw pbscyx
qctdzy rdueaz sevfba tfwgcb ugxhdc
vhyied wizjfe xjakgf ykblhg zlcmih
amdnji bneokj cofplk dpgqml eqhrnm

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: frison
Cipher: uirhlm

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: frison

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: frison
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: frison
Cipher: sevfba

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: frison
Cipher: 122442344333

Extended Methods:
Method #1

Plaintext: frison
method variations:

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

Read more ...
Method #3

Plaintext: frison
method variations:
gtmtnc tmtncg mtncgt
tncgtm ncgtmt cgtmtn

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: frison

all 720 cipher variations:
frison frisno friosn frions frinos frinso frsion frsino frsoin frsoni frsnoi
frsnio frosin frosni froisn froins fronis fronsi frnsoi frnsio frnosi frnois
frnios frniso firson firsno firosn firons firnos firnso fisron fisrno fisorn
fisonr fisnor fisnro fiosrn fiosnr fiorsn fiorns fionrs fionsr finsor finsro
finosr finors finros finrso fsiron fsirno fsiorn fsionr fsinor fsinro fsrion
fsrino fsroin fsroni fsrnoi fsrnio fsorin fsorni fsoirn fsoinr fsonir fsonri
fsnroi fsnrio fsnori fsnoir fsnior fsniro foisrn foisnr foirsn foirns foinrs
foinsr fosirn fosinr fosrin fosrni fosnri fosnir forsin forsni forisn forins
fornis fornsi fonsri fonsir fonrsi fonris fonirs fonisr fnisor fnisro fniosr
fniors fniros fnirso fnsior fnsiro fnsoir fnsori fnsroi fnsrio fnosir fnosri
fnoisr fnoirs fnoris fnorsi fnrsoi fnrsio fnrosi fnrois fnrios fnriso rfison
rfisno rfiosn rfions rfinos rfinso rfsion rfsino rfsoin rfsoni rfsnoi rfsnio
rfosin rfosni rfoisn rfoins rfonis rfonsi rfnsoi rfnsio rfnosi rfnois rfnios
rfniso rifson rifsno rifosn rifons rifnos rifnso risfon risfno risofn risonf
risnof risnfo riosfn riosnf riofsn riofns rionfs rionsf rinsof rinsfo rinosf
rinofs rinfos rinfso rsifon rsifno rsiofn rsionf rsinof rsinfo rsfion rsfino
rsfoin rsfoni rsfnoi rsfnio rsofin rsofni rsoifn rsoinf rsonif rsonfi rsnfoi
rsnfio rsnofi rsnoif rsniof rsnifo roisfn roisnf roifsn roifns roinfs roinsf
rosifn rosinf rosfin rosfni rosnfi rosnif rofsin rofsni rofisn rofins rofnis
rofnsi ronsfi ronsif ronfsi ronfis ronifs ronisf rnisof rnisfo rniosf rniofs
rnifos rnifso rnsiof rnsifo rnsoif rnsofi rnsfoi rnsfio rnosif rnosfi rnoisf
rnoifs rnofis rnofsi rnfsoi rnfsio rnfosi rnfois rnfios rnfiso irfson irfsno
irfosn irfons irfnos irfnso irsfon irsfno irsofn irsonf irsnof irsnfo irosfn
irosnf irofsn irofns ironfs ironsf irnsof irnsfo irnosf irnofs irnfos irnfso
ifrson ifrsno ifrosn ifrons ifrnos ifrnso ifsron ifsrno ifsorn ifsonr ifsnor
ifsnro ifosrn ifosnr iforsn iforns ifonrs ifonsr ifnsor ifnsro ifnosr ifnors
ifnros ifnrso isfron isfrno isforn isfonr isfnor isfnro isrfon isrfno isrofn
isronf isrnof isrnfo isorfn isornf isofrn isofnr isonfr isonrf isnrof isnrfo
isnorf isnofr isnfor isnfro iofsrn iofsnr iofrsn iofrns iofnrs iofnsr iosfrn
iosfnr iosrfn iosrnf iosnrf iosnfr iorsfn iorsnf iorfsn iorfns iornfs iornsf
ionsrf ionsfr ionrsf ionrfs ionfrs ionfsr infsor infsro infosr infors infros
infrso insfor insfro insofr insorf insrof insrfo inosfr inosrf inofsr inofrs
inorfs inorsf inrsof inrsfo inrosf inrofs inrfos inrfso srifon srifno sriofn
srionf srinof srinfo srfion srfino srfoin srfoni srfnoi srfnio srofin srofni
sroifn sroinf sronif sronfi srnfoi srnfio srnofi srnoif srniof srnifo sirfon
sirfno sirofn sironf sirnof sirnfo sifron sifrno siforn sifonr sifnor sifnro
siofrn siofnr siorfn siornf sionrf sionfr sinfor sinfro sinofr sinorf sinrof
sinrfo sfiron sfirno sfiorn sfionr sfinor sfinro sfrion sfrino sfroin sfroni
sfrnoi sfrnio sforin sforni sfoirn sfoinr sfonir sfonri sfnroi sfnrio sfnori
sfnoir sfnior sfniro soifrn soifnr soirfn soirnf soinrf soinfr sofirn sofinr
sofrin sofrni sofnri sofnir sorfin sorfni sorifn sorinf sornif sornfi sonfri
sonfir sonrfi sonrif sonirf sonifr snifor snifro sniofr sniorf snirof snirfo
snfior snfiro snfoir snfori snfroi snfrio snofir snofri snoifr snoirf snorif
snorfi snrfoi snrfio snrofi snroif snriof snrifo orisfn orisnf orifsn orifns
orinfs orinsf orsifn orsinf orsfin orsfni orsnfi orsnif orfsin orfsni orfisn
orfins orfnis orfnsi ornsfi ornsif ornfsi ornfis ornifs ornisf oirsfn oirsnf
oirfsn oirfns oirnfs oirnsf oisrfn oisrnf oisfrn oisfnr oisnfr oisnrf oifsrn
oifsnr oifrsn oifrns oifnrs oifnsr oinsfr oinsrf oinfsr oinfrs oinrfs oinrsf
osirfn osirnf osifrn osifnr osinfr osinrf osrifn osrinf osrfin osrfni osrnfi
osrnif osfrin osfrni osfirn osfinr osfnir osfnri osnrfi osnrif osnfri osnfir
osnifr osnirf ofisrn ofisnr ofirsn ofirns ofinrs ofinsr ofsirn ofsinr ofsrin
ofsrni ofsnri ofsnir ofrsin ofrsni ofrisn ofrins ofrnis ofrnsi ofnsri ofnsir
ofnrsi ofnris ofnirs ofnisr onisfr onisrf onifsr onifrs onirfs onirsf onsifr
onsirf onsfir onsfri onsrfi onsrif onfsir onfsri onfisr onfirs onfris onfrsi
onrsfi onrsif onrfsi onrfis onrifs onrisf nrisof nrisfo nriosf nriofs nrifos
nrifso nrsiof nrsifo nrsoif nrsofi nrsfoi nrsfio nrosif nrosfi nroisf nroifs
nrofis nrofsi nrfsoi nrfsio nrfosi nrfois nrfios nrfiso nirsof nirsfo nirosf
nirofs nirfos nirfso nisrof nisrfo nisorf nisofr nisfor nisfro niosrf niosfr
niorsf niorfs niofrs niofsr nifsor nifsro nifosr nifors nifros nifrso nsirof
nsirfo nsiorf nsiofr nsifor nsifro nsriof nsrifo nsroif nsrofi nsrfoi nsrfio
nsorif nsorfi nsoirf nsoifr nsofir nsofri nsfroi nsfrio nsfori nsfoir nsfior
nsfiro noisrf noisfr noirsf noirfs noifrs noifsr nosirf nosifr nosrif nosrfi
nosfri nosfir norsif norsfi norisf norifs norfis norfsi nofsri nofsir nofrsi
nofris nofirs nofisr nfisor nfisro nfiosr nfiors nfiros nfirso nfsior nfsiro
nfsoir nfsori nfsroi nfsrio nfosir nfosri nfoisr nfoirs nforis nforsi nfrsoi
nfrsio nfrosi nfrois nfrios nfriso

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

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