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: byther
cipher variations:
czuifs davjgt ebwkhu fcxliv gdymjw
heznkx ifaoly jgbpmz khcqna lidrob
mjespc nkftqd olgure pmhvsf qniwtg
rojxuh spkyvi tqlzwj urmaxk vsnbyl
wtoczm xupdan yvqebo zwrfcp axsgdq

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: byther
Cipher: ybgsvi

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: byther

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: byther
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: byther
Cipher: olgure

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: byther
Cipher: 214544325124

Extended Methods:
Method #1

Plaintext: byther
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
b y t h e r 
2 4 4 3 5 2 
1 5 4 2 1 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: byther
Cipher: rokviq

Read more ...
Method #3

Plaintext: byther
method variations:
quowfi uowfiq owfiqu
wfiquo fiquow iquowf

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: byther

all 720 cipher variations:
byther bythre bytehr byterh bytreh bytrhe byhter byhtre byhetr byhert byhret
byhrte byehtr byehrt byethr byetrh byerth byerht byrhet byrhte byreht byreth
byrteh byrthe btyher btyhre btyehr btyerh btyreh btyrhe bthyer bthyre btheyr
bthery bthrey bthrye btehyr btehry bteyhr bteyrh bteryh bterhy btrhey btrhye
btrehy btreyh btryeh btryhe bhtyer bhtyre bhteyr bhtery bhtrey bhtrye bhyter
bhytre bhyetr bhyert bhyret bhyrte bheytr bheyrt bhetyr bhetry bherty bheryt
bhryet bhryte bhreyt bhrety bhrtey bhrtye bethyr bethry betyhr betyrh betryh
betrhy behtyr behtry behytr behyrt behryt behrty beyhtr beyhrt beythr beytrh
beyrth beyrht berhyt berhty beryht beryth bertyh berthy brthey brthye brtehy
brteyh brtyeh brtyhe brhtey brhtye brhety brheyt brhyet brhyte brehty brehyt
brethy bretyh breyth breyht bryhet bryhte bryeht bryeth bryteh brythe ybther
ybthre ybtehr ybterh ybtreh ybtrhe ybhter ybhtre ybhetr ybhert ybhret ybhrte
ybehtr ybehrt ybethr ybetrh yberth yberht ybrhet ybrhte ybreht ybreth ybrteh
ybrthe ytbher ytbhre ytbehr ytberh ytbreh ytbrhe ythber ythbre ythebr ytherb
ythreb ythrbe ytehbr ytehrb ytebhr ytebrh yterbh yterhb ytrheb ytrhbe ytrehb
ytrebh ytrbeh ytrbhe yhtber yhtbre yhtebr yhterb yhtreb yhtrbe yhbter yhbtre
yhbetr yhbert yhbret yhbrte yhebtr yhebrt yhetbr yhetrb yhertb yherbt yhrbet
yhrbte yhrebt yhretb yhrteb yhrtbe yethbr yethrb yetbhr yetbrh yetrbh yetrhb
yehtbr yehtrb yehbtr yehbrt yehrbt yehrtb yebhtr yebhrt yebthr yebtrh yebrth
yebrht yerhbt yerhtb yerbht yerbth yertbh yerthb yrtheb yrthbe yrtehb yrtebh
yrtbeh yrtbhe yrhteb yrhtbe yrhetb yrhebt yrhbet yrhbte yrehtb yrehbt yrethb
yretbh yrebth yrebht yrbhet yrbhte yrbeht yrbeth yrbteh yrbthe tybher tybhre
tybehr tyberh tybreh tybrhe tyhber tyhbre tyhebr tyherb tyhreb tyhrbe tyehbr
tyehrb tyebhr tyebrh tyerbh tyerhb tyrheb tyrhbe tyrehb tyrebh tyrbeh tyrbhe
tbyher tbyhre tbyehr tbyerh tbyreh tbyrhe tbhyer tbhyre tbheyr tbhery tbhrey
tbhrye tbehyr tbehry tbeyhr tbeyrh tberyh tberhy tbrhey tbrhye tbrehy tbreyh
tbryeh tbryhe thbyer thbyre thbeyr thbery thbrey thbrye thyber thybre thyebr
thyerb thyreb thyrbe theybr theyrb thebyr thebry therby theryb thryeb thrybe
threyb threby thrbey thrbye tebhyr tebhry tebyhr tebyrh tebryh tebrhy tehbyr
tehbry tehybr tehyrb tehryb tehrby teyhbr teyhrb teybhr teybrh teyrbh teyrhb
terhyb terhby teryhb terybh terbyh terbhy trbhey trbhye trbehy trbeyh trbyeh
trbyhe trhbey trhbye trheby trheyb trhyeb trhybe trehby trehyb trebhy trebyh
treybh treyhb tryheb tryhbe tryehb tryebh trybeh trybhe hytber hytbre hytebr
hyterb hytreb hytrbe hybter hybtre hybetr hybert hybret hybrte hyebtr hyebrt
hyetbr hyetrb hyertb hyerbt hyrbet hyrbte hyrebt hyretb hyrteb hyrtbe htyber
htybre htyebr htyerb htyreb htyrbe htbyer htbyre htbeyr htbery htbrey htbrye
htebyr htebry hteybr hteyrb hteryb hterby htrbey htrbye htreby htreyb htryeb
htrybe hbtyer hbtyre hbteyr hbtery hbtrey hbtrye hbyter hbytre hbyetr hbyert
hbyret hbyrte hbeytr hbeyrt hbetyr hbetry hberty hberyt hbryet hbryte hbreyt
hbrety hbrtey hbrtye hetbyr hetbry hetybr hetyrb hetryb hetrby hebtyr hebtry
hebytr hebyrt hebryt hebrty heybtr heybrt heytbr heytrb heyrtb heyrbt herbyt
herbty herybt herytb hertyb hertby hrtbey hrtbye hrteby hrteyb hrtyeb hrtybe
hrbtey hrbtye hrbety hrbeyt hrbyet hrbyte hrebty hrebyt hretby hretyb hreytb
hreybt hrybet hrybte hryebt hryetb hryteb hrytbe eythbr eythrb eytbhr eytbrh
eytrbh eytrhb eyhtbr eyhtrb eyhbtr eyhbrt eyhrbt eyhrtb eybhtr eybhrt eybthr
eybtrh eybrth eybrht eyrhbt eyrhtb eyrbht eyrbth eyrtbh eyrthb etyhbr etyhrb
etybhr etybrh etyrbh etyrhb ethybr ethyrb ethbyr ethbry ethrby ethryb etbhyr
etbhry etbyhr etbyrh etbryh etbrhy etrhby etrhyb etrbhy etrbyh etrybh etryhb
ehtybr ehtyrb ehtbyr ehtbry ehtrby ehtryb ehytbr ehytrb ehybtr ehybrt ehyrbt
ehyrtb ehbytr ehbyrt ehbtyr ehbtry ehbrty ehbryt ehrybt ehrytb ehrbyt ehrbty
ehrtby ehrtyb ebthyr ebthry ebtyhr ebtyrh ebtryh ebtrhy ebhtyr ebhtry ebhytr
ebhyrt ebhryt ebhrty ebyhtr ebyhrt ebythr ebytrh ebyrth ebyrht ebrhyt ebrhty
ebryht ebryth ebrtyh ebrthy erthby erthyb ertbhy ertbyh ertybh ertyhb erhtby
erhtyb erhbty erhbyt erhybt erhytb erbhty erbhyt erbthy erbtyh erbyth erbyht
eryhbt eryhtb erybht erybth erytbh erythb rytheb rythbe rytehb rytebh rytbeh
rytbhe ryhteb ryhtbe ryhetb ryhebt ryhbet ryhbte ryehtb ryehbt ryethb ryetbh
ryebth ryebht rybhet rybhte rybeht rybeth rybteh rybthe rtyheb rtyhbe rtyehb
rtyebh rtybeh rtybhe rthyeb rthybe rtheyb rtheby rthbey rthbye rtehyb rtehby
rteyhb rteybh rtebyh rtebhy rtbhey rtbhye rtbehy rtbeyh rtbyeh rtbyhe rhtyeb
rhtybe rhteyb rhteby rhtbey rhtbye rhyteb rhytbe rhyetb rhyebt rhybet rhybte
rheytb rheybt rhetyb rhetby rhebty rhebyt rhbyet rhbyte rhbeyt rhbety rhbtey
rhbtye rethyb rethby retyhb retybh retbyh retbhy rehtyb rehtby rehytb rehybt
rehbyt rehbty reyhtb reyhbt reythb reytbh reybth reybht rebhyt rebhty rebyht
rebyth rebtyh rebthy rbthey rbthye rbtehy rbteyh rbtyeh rbtyhe rbhtey rbhtye
rbhety rbheyt rbhyet rbhyte rbehty rbehyt rbethy rbetyh rbeyth rbeyht rbyhet
rbyhte rbyeht rbyeth rbyteh rbythe

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

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