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: skroup
cipher variations:
tlspvq umtqwr vnurxs wovsyt xpwtzu
yqxuav zryvbw aszwcx btaxdy cubyez
dvczfa ewdagb fxebhc gyfcid hzgdje
iahekf jbiflg kcjgmh ldkhni melioj
nfmjpk ognkql pholrm qipmsn rjqnto

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: skroup
Cipher: hpilfk

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: skroup

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: skroup
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: skroup
Cipher: fxebhc

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: skroup
Cipher: 345224435453

Extended Methods:
Method #1

Plaintext: skroup
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
s k r o u p 
3 5 2 4 5 5 
4 2 4 3 4 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: skroup
Cipher: xrzioo

Read more ...
Method #3

Plaintext: skroup
method variations:
ygtxyn gtxyny txynyg
xynygt ynygtx nygtxy

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: skroup

all 720 cipher variations:
skroup skropu skruop skrupo skrpuo skrpou skorup skorpu skourp skoupr skopur
skopru skuorp skuopr skurop skurpo skupro skupor skpour skporu skpuor skpuro
skpruo skprou srkoup srkopu srkuop srkupo srkpuo srkpou srokup srokpu sroukp
sroupk sropuk sropku sruokp sruopk srukop srukpo srupko srupok srpouk srpoku
srpuok srpuko srpkuo srpkou sorkup sorkpu sorukp sorupk sorpuk sorpku sokrup
sokrpu sokurp sokupr sokpur sokpru soukrp soukpr sourkp sourpk souprk soupkr
sopkur sopkru sopukr sopurk sopruk soprku surokp suropk surkop surkpo surpko
surpok suorkp suorpk suokrp suokpr suopkr suoprk sukorp sukopr sukrop sukrpo
sukpro sukpor supokr supork supkor supkro suprko suprok sprouk sproku spruok
spruko sprkuo sprkou sporuk sporku spourk spoukr spokur spokru spuork spuokr
spurok spurko spukro spukor spkour spkoru spkuor spkuro spkruo spkrou ksroup
ksropu ksruop ksrupo ksrpuo ksrpou ksorup ksorpu ksourp ksoupr ksopur ksopru
ksuorp ksuopr ksurop ksurpo ksupro ksupor kspour ksporu kspuor kspuro kspruo
ksprou krsoup krsopu krsuop krsupo krspuo krspou krosup krospu krousp kroups
kropus kropsu kruosp kruops krusop kruspo krupso krupos krpous krposu krpuos
krpuso krpsuo krpsou korsup korspu korusp korups korpus korpsu kosrup kosrpu
kosurp kosupr kospur kospru kousrp kouspr koursp kourps kouprs koupsr kopsur
kopsru kopusr kopurs koprus koprsu kurosp kurops kursop kurspo kurpso kurpos
kuorsp kuorps kuosrp kuospr kuopsr kuoprs kusorp kusopr kusrop kusrpo kuspro
kuspor kuposr kupors kupsor kupsro kuprso kupros kprous kprosu kpruos kpruso
kprsuo kprsou kporus kporsu kpours kpousr kposur kposru kpuors kpuosr kpuros
kpurso kpusro kpusor kpsour kpsoru kpsuor kpsuro kpsruo kpsrou rksoup rksopu
rksuop rksupo rkspuo rkspou rkosup rkospu rkousp rkoups rkopus rkopsu rkuosp
rkuops rkusop rkuspo rkupso rkupos rkpous rkposu rkpuos rkpuso rkpsuo rkpsou
rskoup rskopu rskuop rskupo rskpuo rskpou rsokup rsokpu rsoukp rsoupk rsopuk
rsopku rsuokp rsuopk rsukop rsukpo rsupko rsupok rspouk rspoku rspuok rspuko
rspkuo rspkou roskup roskpu rosukp rosupk rospuk rospku roksup rokspu rokusp
rokups rokpus rokpsu rouksp roukps rouskp rouspk roupsk roupks ropkus ropksu
ropuks ropusk ropsuk ropsku rusokp rusopk ruskop ruskpo ruspko ruspok ruoskp
ruospk ruoksp ruokps ruopks ruopsk rukosp rukops ruksop rukspo rukpso rukpos
rupoks ruposk rupkos rupkso rupsko rupsok rpsouk rpsoku rpsuok rpsuko rpskuo
rpskou rposuk rposku rpousk rpouks rpokus rpoksu rpuosk rpuoks rpusok rpusko
rpukso rpukos rpkous rpkosu rpkuos rpkuso rpksuo rpksou okrsup okrspu okrusp
okrups okrpus okrpsu oksrup oksrpu oksurp oksupr okspur okspru okusrp okuspr
okursp okurps okuprs okupsr okpsur okpsru okpusr okpurs okprus okprsu orksup
orkspu orkusp orkups orkpus orkpsu orskup orskpu orsukp orsupk orspuk orspku
oruskp oruspk oruksp orukps orupks orupsk orpsuk orpsku orpusk orpuks orpkus
orpksu osrkup osrkpu osrukp osrupk osrpuk osrpku oskrup oskrpu oskurp oskupr
oskpur oskpru osukrp osukpr osurkp osurpk osuprk osupkr ospkur ospkru ospukr
ospurk ospruk osprku ourskp ourspk ourksp ourkps ourpks ourpsk ousrkp ousrpk
ouskrp ouskpr ouspkr ousprk ouksrp oukspr oukrsp oukrps oukprs oukpsr oupskr
oupsrk oupksr oupkrs ouprks ouprsk oprsuk oprsku oprusk opruks oprkus oprksu
opsruk opsrku opsurk opsukr opskur opskru opusrk opuskr opursk opurks opukrs
opuksr opksur opksru opkusr opkurs opkrus opkrsu ukrosp ukrops ukrsop ukrspo
ukrpso ukrpos ukorsp ukorps ukosrp ukospr ukopsr ukoprs uksorp uksopr uksrop
uksrpo ukspro ukspor ukposr ukpors ukpsor ukpsro ukprso ukpros urkosp urkops
urksop urkspo urkpso urkpos uroksp urokps uroskp urospk uropsk uropks ursokp
ursopk urskop urskpo urspko urspok urposk urpoks urpsok urpsko urpkso urpkos
uorksp uorkps uorskp uorspk uorpsk uorpks uokrsp uokrps uoksrp uokspr uokpsr
uokprs uoskrp uoskpr uosrkp uosrpk uosprk uospkr uopksr uopkrs uopskr uopsrk
uoprsk uoprks usrokp usropk usrkop usrkpo usrpko usrpok usorkp usorpk usokrp
usokpr usopkr usoprk uskorp uskopr uskrop uskrpo uskpro uskpor uspokr uspork
uspkor uspkro usprko usprok uprosk uproks uprsok uprsko uprkso uprkos uporsk
uporks uposrk uposkr upoksr upokrs upsork upsokr upsrok upsrko upskro upskor
upkosr upkors upksor upksro upkrso upkros pkrous pkrosu pkruos pkruso pkrsuo
pkrsou pkorus pkorsu pkours pkousr pkosur pkosru pkuors pkuosr pkuros pkurso
pkusro pkusor pksour pksoru pksuor pksuro pksruo pksrou prkous prkosu prkuos
prkuso prksuo prksou prokus proksu prouks prousk prosuk prosku pruoks pruosk
prukos prukso prusko prusok prsouk prsoku prsuok prsuko prskuo prskou porkus
porksu poruks porusk porsuk porsku pokrus pokrsu pokurs pokusr poksur poksru
poukrs pouksr pourks poursk pousrk pouskr poskur poskru posukr posurk posruk
posrku puroks purosk purkos purkso pursko pursok puorks puorsk puokrs puoksr
puoskr puosrk pukors pukosr pukros pukrso puksro puksor pusokr pusork puskor
puskro pusrko pusrok psrouk psroku psruok psruko psrkuo psrkou psoruk psorku
psourk psoukr psokur psokru psuork psuokr psurok psurko psukro psukor pskour
pskoru pskuor pskuro pskruo pskrou

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

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