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: disney
cipher variations:
ejtofz fkupga glvqhb hmwric inxsjd
joytke kpzulf lqavmg mrbwnh nscxoi
otdypj puezqk qvfarl rwgbsm sxhctn
tyiduo uzjevp vakfwq wblgxr xcmhys
ydnizt zeojau afpkbv bgqlcw chrmdx

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: disney
Cipher: wrhmvb

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: disney

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: disney
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: disney
Cipher: qvfarl

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: disney
Cipher: 414234335145

Extended Methods:
Method #1

Plaintext: disney
method variations:

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

Read more ...
Method #3

Plaintext: disney
method variations:
qmoxqu moxquq oxquqm
xquqmo quqmox uqmoxq

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: disney

all 720 cipher variations:
disney disnye diseny diseyn disyen disyne dinsey dinsye dinesy dineys dinyes
dinyse diensy dienys diesny diesyn dieysn dieyns diynes diynse diyens diyesn
diysen diysne dsiney dsinye dsieny dsieyn dsiyen dsiyne dsniey dsniye dsneiy
dsneyi dsnyei dsnyie dseniy dsenyi dseiny dseiyn dseyin dseyni dsynei dsynie
dsyeni dsyein dsyien dsyine dnsiey dnsiye dnseiy dnseyi dnsyei dnsyie dnisey
dnisye dniesy dnieys dniyes dniyse dneisy dneiys dnesiy dnesyi dneysi dneyis
dnyies dnyise dnyeis dnyesi dnysei dnysie desniy desnyi desiny desiyn desyin
desyni densiy densyi denisy deniys denyis denysi deinsy deinys deisny deisyn
deiysn deiyns deynis deynsi deyins deyisn deysin deysni dysnei dysnie dyseni
dysein dysien dysine dynsei dynsie dynesi dyneis dynies dynise dyensi dyenis
dyesni dyesin dyeisn dyeins dyines dyinse dyiens dyiesn dyisen dyisne idsney
idsnye idseny idseyn idsyen idsyne idnsey idnsye idnesy idneys idnyes idnyse
idensy idenys idesny idesyn ideysn ideyns idynes idynse idyens idyesn idysen
idysne isdney isdnye isdeny isdeyn isdyen isdyne isndey isndye isnedy isneyd
isnyed isnyde isendy isenyd isedny isedyn iseydn iseynd isyned isynde isyend
isyedn isyden isydne insdey insdye insedy inseyd insyed insyde indsey indsye
indesy indeys indyes indyse inedsy inedys inesdy inesyd ineysd ineyds inydes
inydse inyeds inyesd inysed inysde iesndy iesnyd iesdny iesdyn iesydn iesynd
iensdy iensyd iendsy iendys ienyds ienysd iednsy iednys iedsny iedsyn iedysn
iedyns ieynds ieynsd ieydns ieydsn ieysdn ieysnd iysned iysnde iysend iysedn
iysden iysdne iynsed iynsde iynesd iyneds iyndes iyndse iyensd iyends iyesnd
iyesdn iyedsn iyedns iydnes iydnse iydens iydesn iydsen iydsne sidney sidnye
sideny sideyn sidyen sidyne sindey sindye sinedy sineyd sinyed sinyde siendy
sienyd siedny siedyn sieydn sieynd siyned siynde siyend siyedn siyden siydne
sdiney sdinye sdieny sdieyn sdiyen sdiyne sdniey sdniye sdneiy sdneyi sdnyei
sdnyie sdeniy sdenyi sdeiny sdeiyn sdeyin sdeyni sdynei sdynie sdyeni sdyein
sdyien sdyine sndiey sndiye sndeiy sndeyi sndyei sndyie snidey snidye sniedy
snieyd sniyed sniyde sneidy sneiyd snediy snedyi sneydi sneyid snyied snyide
snyeid snyedi snydei snydie sedniy sednyi sediny sediyn sedyin sedyni sendiy
sendyi senidy seniyd senyid senydi seindy seinyd seidny seidyn seiydn seiynd
seynid seyndi seyind seyidn seydin seydni sydnei sydnie sydeni sydein sydien
sydine syndei syndie synedi syneid synied synide syendi syenid syedni syedin
syeidn syeind syined syinde syiend syiedn syiden syidne nisdey nisdye nisedy
niseyd nisyed nisyde nidsey nidsye nidesy nideys nidyes nidyse niedsy niedys
niesdy niesyd nieysd nieyds niydes niydse niyeds niyesd niysed niysde nsidey
nsidye nsiedy nsieyd nsiyed nsiyde nsdiey nsdiye nsdeiy nsdeyi nsdyei nsdyie
nsediy nsedyi nseidy nseiyd nseyid nseydi nsydei nsydie nsyedi nsyeid nsyied
nsyide ndsiey ndsiye ndseiy ndseyi ndsyei ndsyie ndisey ndisye ndiesy ndieys
ndiyes ndiyse ndeisy ndeiys ndesiy ndesyi ndeysi ndeyis ndyies ndyise ndyeis
ndyesi ndysei ndysie nesdiy nesdyi nesidy nesiyd nesyid nesydi nedsiy nedsyi
nedisy nediys nedyis nedysi neidsy neidys neisdy neisyd neiysd neiyds neydis
neydsi neyids neyisd neysid neysdi nysdei nysdie nysedi nyseid nysied nyside
nydsei nydsie nydesi nydeis nydies nydise nyedsi nyedis nyesdi nyesid nyeisd
nyeids nyides nyidse nyieds nyiesd nyised nyisde eisndy eisnyd eisdny eisdyn
eisydn eisynd einsdy einsyd eindsy eindys einyds einysd eidnsy eidnys eidsny
eidsyn eidysn eidyns eiynds eiynsd eiydns eiydsn eiysdn eiysnd esindy esinyd
esidny esidyn esiydn esiynd esnidy esniyd esndiy esndyi esnydi esnyid esdniy
esdnyi esdiny esdiyn esdyin esdyni esyndi esynid esydni esydin esyidn esyind
ensidy ensiyd ensdiy ensdyi ensydi ensyid enisdy enisyd enidsy enidys eniyds
eniysd endisy endiys endsiy endsyi endysi endyis enyids enyisd enydis enydsi
enysdi enysid edsniy edsnyi edsiny edsiyn edsyin edsyni ednsiy ednsyi ednisy
edniys ednyis ednysi edinsy edinys edisny edisyn ediysn ediyns edynis edynsi
edyins edyisn edysin edysni eysndi eysnid eysdni eysdin eysidn eysind eynsdi
eynsid eyndsi eyndis eynids eynisd eydnsi eydnis eydsni eydsin eydisn eydins
eyinds eyinsd eyidns eyidsn eyisdn eyisnd yisned yisnde yisend yisedn yisden
yisdne yinsed yinsde yinesd yineds yindes yindse yiensd yiends yiesnd yiesdn
yiedsn yiedns yidnes yidnse yidens yidesn yidsen yidsne ysined ysinde ysiend
ysiedn ysiden ysidne ysnied ysnide ysneid ysnedi ysndei ysndie ysenid ysendi
yseind yseidn ysedin ysedni ysdnei ysdnie ysdeni ysdein ysdien ysdine ynsied
ynside ynseid ynsedi ynsdei ynsdie ynised ynisde yniesd ynieds ynides ynidse
yneisd yneids ynesid ynesdi ynedsi ynedis yndies yndise yndeis yndesi yndsei
yndsie yesnid yesndi yesind yesidn yesdin yesdni yensid yensdi yenisd yenids
yendis yendsi yeinsd yeinds yeisnd yeisdn yeidsn yeidns yednis yednsi yedins
yedisn yedsin yedsni ydsnei ydsnie ydseni ydsein ydsien ydsine ydnsei ydnsie
ydnesi ydneis ydnies ydnise ydensi ydenis ydesni ydesin ydeisn ydeins ydines
ydinse ydiens ydiesn ydisen ydisne

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

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