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: hymned
cipher variations:
iznofe jaopgf kbpqhg lcqrih mdrsji
nestkj oftulk pguvml qhvwnm riwxon
sjxypo tkyzqp ulzarq vmabsr wnbcts
xocdut ypdevu zqefwv arfgxw bsghyx
cthizy duijaz evjkba fwklcb gxlmdc

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: hymned
Cipher: sbnmvw

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: hymned

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: hymned
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: hymned
Cipher: ulzarq

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: hymned
Cipher: 324523335141

Extended Methods:
Method #1

Plaintext: hymned
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
h y m n e d 
3 4 2 3 5 4 
2 5 3 3 1 1 
They are then read out in rows:
Then divided up into pairs again, and the pairs turned back into letters using the square:
Plain: hymned
Cipher: smuwna

Read more ...
Method #3

Plaintext: hymned
method variations:
rknxql knxqlr nxqlrk
xqlrkn qlrknx lrknxq

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: hymned

all 720 cipher variations:
hymned hymnde hymend hymedn hymden hymdne hynmed hynmde hynemd hynedm hyndem
hyndme hyenmd hyendm hyemnd hyemdn hyedmn hyednm hydnem hydnme hydenm hydemn
hydmen hydmne hmyned hmynde hmyend hmyedn hmyden hmydne hmnyed hmnyde hmneyd
hmnedy hmndey hmndye hmenyd hmendy hmeynd hmeydn hmedyn hmedny hmdney hmdnye
hmdeny hmdeyn hmdyen hmdyne hnmyed hnmyde hnmeyd hnmedy hnmdey hnmdye hnymed
hnymde hnyemd hnyedm hnydem hnydme hneymd hneydm hnemyd hnemdy hnedmy hnedym
hndyem hndyme hndeym hndemy hndmey hndmye hemnyd hemndy hemynd hemydn hemdyn
hemdny henmyd henmdy henymd henydm hendym hendmy heynmd heyndm heymnd heymdn
heydmn heydnm hednym hednmy hedynm hedymn hedmyn hedmny hdmney hdmnye hdmeny
hdmeyn hdmyen hdmyne hdnmey hdnmye hdnemy hdneym hdnyem hdnyme hdenmy hdenym
hdemny hdemyn hdeymn hdeynm hdynem hdynme hdyenm hdyemn hdymen hdymne yhmned
yhmnde yhmend yhmedn yhmden yhmdne yhnmed yhnmde yhnemd yhnedm yhndem yhndme
yhenmd yhendm yhemnd yhemdn yhedmn yhednm yhdnem yhdnme yhdenm yhdemn yhdmen
yhdmne ymhned ymhnde ymhend ymhedn ymhden ymhdne ymnhed ymnhde ymnehd ymnedh
ymndeh ymndhe ymenhd ymendh ymehnd ymehdn ymedhn ymednh ymdneh ymdnhe ymdenh
ymdehn ymdhen ymdhne ynmhed ynmhde ynmehd ynmedh ynmdeh ynmdhe ynhmed ynhmde
ynhemd ynhedm ynhdem ynhdme ynehmd ynehdm ynemhd ynemdh ynedmh ynedhm yndhem
yndhme yndehm yndemh yndmeh yndmhe yemnhd yemndh yemhnd yemhdn yemdhn yemdnh
yenmhd yenmdh yenhmd yenhdm yendhm yendmh yehnmd yehndm yehmnd yehmdn yehdmn
yehdnm yednhm yednmh yedhnm yedhmn yedmhn yedmnh ydmneh ydmnhe ydmenh ydmehn
ydmhen ydmhne ydnmeh ydnmhe ydnemh ydnehm ydnhem ydnhme ydenmh ydenhm ydemnh
ydemhn ydehmn ydehnm ydhnem ydhnme ydhenm ydhemn ydhmen ydhmne myhned myhnde
myhend myhedn myhden myhdne mynhed mynhde mynehd mynedh myndeh myndhe myenhd
myendh myehnd myehdn myedhn myednh mydneh mydnhe mydenh mydehn mydhen mydhne
mhyned mhynde mhyend mhyedn mhyden mhydne mhnyed mhnyde mhneyd mhnedy mhndey
mhndye mhenyd mhendy mheynd mheydn mhedyn mhedny mhdney mhdnye mhdeny mhdeyn
mhdyen mhdyne mnhyed mnhyde mnheyd mnhedy mnhdey mnhdye mnyhed mnyhde mnyehd
mnyedh mnydeh mnydhe mneyhd mneydh mnehyd mnehdy mnedhy mnedyh mndyeh mndyhe
mndeyh mndehy mndhey mndhye mehnyd mehndy mehynd mehydn mehdyn mehdny menhyd
menhdy menyhd menydh mendyh mendhy meynhd meyndh meyhnd meyhdn meydhn meydnh
mednyh mednhy medynh medyhn medhyn medhny mdhney mdhnye mdheny mdheyn mdhyen
mdhyne mdnhey mdnhye mdnehy mdneyh mdnyeh mdnyhe mdenhy mdenyh mdehny mdehyn
mdeyhn mdeynh mdyneh mdynhe mdyenh mdyehn mdyhen mdyhne nymhed nymhde nymehd
nymedh nymdeh nymdhe nyhmed nyhmde nyhemd nyhedm nyhdem nyhdme nyehmd nyehdm
nyemhd nyemdh nyedmh nyedhm nydhem nydhme nydehm nydemh nydmeh nydmhe nmyhed
nmyhde nmyehd nmyedh nmydeh nmydhe nmhyed nmhyde nmheyd nmhedy nmhdey nmhdye
nmehyd nmehdy nmeyhd nmeydh nmedyh nmedhy nmdhey nmdhye nmdehy nmdeyh nmdyeh
nmdyhe nhmyed nhmyde nhmeyd nhmedy nhmdey nhmdye nhymed nhymde nhyemd nhyedm
nhydem nhydme nheymd nheydm nhemyd nhemdy nhedmy nhedym nhdyem nhdyme nhdeym
nhdemy nhdmey nhdmye nemhyd nemhdy nemyhd nemydh nemdyh nemdhy nehmyd nehmdy
nehymd nehydm nehdym nehdmy neyhmd neyhdm neymhd neymdh neydmh neydhm nedhym
nedhmy nedyhm nedymh nedmyh nedmhy ndmhey ndmhye ndmehy ndmeyh ndmyeh ndmyhe
ndhmey ndhmye ndhemy ndheym ndhyem ndhyme ndehmy ndehym ndemhy ndemyh ndeymh
ndeyhm ndyhem ndyhme ndyehm ndyemh ndymeh ndymhe eymnhd eymndh eymhnd eymhdn
eymdhn eymdnh eynmhd eynmdh eynhmd eynhdm eyndhm eyndmh eyhnmd eyhndm eyhmnd
eyhmdn eyhdmn eyhdnm eydnhm eydnmh eydhnm eydhmn eydmhn eydmnh emynhd emyndh
emyhnd emyhdn emydhn emydnh emnyhd emnydh emnhyd emnhdy emndhy emndyh emhnyd
emhndy emhynd emhydn emhdyn emhdny emdnhy emdnyh emdhny emdhyn emdyhn emdynh
enmyhd enmydh enmhyd enmhdy enmdhy enmdyh enymhd enymdh enyhmd enyhdm enydhm
enydmh enhymd enhydm enhmyd enhmdy enhdmy enhdym endyhm endymh endhym endhmy
endmhy endmyh ehmnyd ehmndy ehmynd ehmydn ehmdyn ehmdny ehnmyd ehnmdy ehnymd
ehnydm ehndym ehndmy ehynmd ehyndm ehymnd ehymdn ehydmn ehydnm ehdnym ehdnmy
ehdynm ehdymn ehdmyn ehdmny edmnhy edmnyh edmhny edmhyn edmyhn edmynh ednmhy
ednmyh ednhmy ednhym ednyhm ednymh edhnmy edhnym edhmny edhmyn edhymn edhynm
edynhm edynmh edyhnm edyhmn edymhn edymnh dymneh dymnhe dymenh dymehn dymhen
dymhne dynmeh dynmhe dynemh dynehm dynhem dynhme dyenmh dyenhm dyemnh dyemhn
dyehmn dyehnm dyhnem dyhnme dyhenm dyhemn dyhmen dyhmne dmyneh dmynhe dmyenh
dmyehn dmyhen dmyhne dmnyeh dmnyhe dmneyh dmnehy dmnhey dmnhye dmenyh dmenhy
dmeynh dmeyhn dmehyn dmehny dmhney dmhnye dmheny dmheyn dmhyen dmhyne dnmyeh
dnmyhe dnmeyh dnmehy dnmhey dnmhye dnymeh dnymhe dnyemh dnyehm dnyhem dnyhme
dneymh dneyhm dnemyh dnemhy dnehmy dnehym dnhyem dnhyme dnheym dnhemy dnhmey
dnhmye demnyh demnhy demynh demyhn demhyn demhny denmyh denmhy denymh denyhm
denhym denhmy deynmh deynhm deymnh deymhn deyhmn deyhnm dehnym dehnmy dehynm
dehymn dehmyn dehmny dhmney dhmnye dhmeny dhmeyn dhmyen dhmyne dhnmey dhnmye
dhnemy dhneym dhnyem dhnyme dhenmy dhenym dhemny dhemyn dheymn dheynm dhynem
dhynme dhyenm dhyemn dhymen dhymne

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

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