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: carvel
cipher variations:
dbswfm ectxgn fduyho gevzip hfwajq
igxbkr jhycls kizdmt ljaenu mkbfov
nlcgpw omdhqx pneiry qofjsz rpgkta
sqhlub trimvc usjnwd vtkoxe wulpyf
xvmqzg ywnrah zxosbi ayptcj bzqudk

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: carvel
Cipher: xzievo

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: carvel

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: carvel
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: carvel
Cipher: pneiry

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: carvel
Cipher: 311124155113

Extended Methods:
Method #1

Plaintext: carvel
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
c a r v e l 
3 1 2 1 5 1 
1 1 4 5 1 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: carvel
Cipher: cbeayl

Read more ...
Method #3

Plaintext: carvel
method variations:
afdzan fdzana dzanaf
zanafd anafdz nafdza

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: carvel

all 720 cipher variations:
carvel carvle carevl carelv carlev carlve cavrel cavrle caverl cavelr cavler
cavlre caevrl caevlr caervl caerlv caelrv caelvr calver calvre calevr calerv
calrev calrve cravel cravle craevl craelv cralev cralve crvael crvale crveal
crvela crvlea crvlae creval crevla creavl crealv crelav crelva crlvea crlvae
crleva crleav crlaev crlave cvrael cvrale cvreal cvrela cvrlea cvrlae cvarel
cvarle cvaerl cvaelr cvaler cvalre cvearl cvealr cveral cverla cvelra cvelar
cvlaer cvlare cvlear cvlera cvlrea cvlrae cerval cervla ceravl ceralv cerlav
cerlva cevral cevrla cevarl cevalr cevlar cevlra ceavrl ceavlr cearvl cearlv
cealrv cealvr celvar celvra celavr celarv celrav celrva clrvea clrvae clreva
clreav clraev clrave clvrea clvrae clvera clvear clvaer clvare clevra clevar
clerva clerav clearv cleavr claver clavre claevr claerv clarev clarve acrvel
acrvle acrevl acrelv acrlev acrlve acvrel acvrle acverl acvelr acvler acvlre
acevrl acevlr acervl acerlv acelrv acelvr aclver aclvre aclevr aclerv aclrev
aclrve arcvel arcvle arcevl arcelv arclev arclve arvcel arvcle arvecl arvelc
arvlec arvlce arevcl arevlc arecvl areclv arelcv arelvc arlvec arlvce arlevc
arlecv arlcev arlcve avrcel avrcle avrecl avrelc avrlec avrlce avcrel avcrle
avcerl avcelr avcler avclre avecrl aveclr avercl averlc avelrc avelcr avlcer
avlcre avlecr avlerc avlrec avlrce aervcl aervlc aercvl aerclv aerlcv aerlvc
aevrcl aevrlc aevcrl aevclr aevlcr aevlrc aecvrl aecvlr aecrvl aecrlv aeclrv
aeclvr aelvcr aelvrc aelcvr aelcrv aelrcv aelrvc alrvec alrvce alrevc alrecv
alrcev alrcve alvrec alvrce alverc alvecr alvcer alvcre alevrc alevcr alervc
alercv alecrv alecvr alcver alcvre alcevr alcerv alcrev alcrve racvel racvle
racevl racelv raclev raclve ravcel ravcle ravecl ravelc ravlec ravlce raevcl
raevlc raecvl raeclv raelcv raelvc ralvec ralvce ralevc ralecv ralcev ralcve
rcavel rcavle rcaevl rcaelv rcalev rcalve rcvael rcvale rcveal rcvela rcvlea
rcvlae rceval rcevla rceavl rcealv rcelav rcelva rclvea rclvae rcleva rcleav
rclaev rclave rvcael rvcale rvceal rvcela rvclea rvclae rvacel rvacle rvaecl
rvaelc rvalec rvalce rveacl rvealc rvecal rvecla rvelca rvelac rvlaec rvlace
rvleac rvleca rvlcea rvlcae recval recvla recavl recalv reclav reclva revcal
revcla revacl revalc revlac revlca reavcl reavlc reacvl reaclv realcv realvc
relvac relvca relavc relacv relcav relcva rlcvea rlcvae rlceva rlceav rlcaev
rlcave rlvcea rlvcae rlveca rlveac rlvaec rlvace rlevca rlevac rlecva rlecav
rleacv rleavc rlavec rlavce rlaevc rlaecv rlacev rlacve varcel varcle varecl
varelc varlec varlce vacrel vacrle vacerl vacelr vacler vaclre vaecrl vaeclr
vaercl vaerlc vaelrc vaelcr valcer valcre valecr valerc valrec valrce vracel
vracle vraecl vraelc vralec vralce vrcael vrcale vrceal vrcela vrclea vrclae
vrecal vrecla vreacl vrealc vrelac vrelca vrlcea vrlcae vrleca vrleac vrlaec
vrlace vcrael vcrale vcreal vcrela vcrlea vcrlae vcarel vcarle vcaerl vcaelr
vcaler vcalre vcearl vcealr vceral vcerla vcelra vcelar vclaer vclare vclear
vclera vclrea vclrae vercal vercla veracl veralc verlac verlca vecral vecrla
vecarl vecalr veclar veclra veacrl veaclr vearcl vearlc vealrc vealcr velcar
velcra velacr velarc velrac velrca vlrcea vlrcae vlreca vlreac vlraec vlrace
vlcrea vlcrae vlcera vlcear vlcaer vlcare vlecra vlecar vlerca vlerac vlearc
vleacr vlacer vlacre vlaecr vlaerc vlarec vlarce earvcl earvlc earcvl earclv
earlcv earlvc eavrcl eavrlc eavcrl eavclr eavlcr eavlrc eacvrl eacvlr eacrvl
eacrlv eaclrv eaclvr ealvcr ealvrc ealcvr ealcrv ealrcv ealrvc eravcl eravlc
eracvl eraclv eralcv eralvc ervacl ervalc ervcal ervcla ervlca ervlac ercval
ercvla ercavl ercalv erclav erclva erlvca erlvac erlcva erlcav erlacv erlavc
evracl evralc evrcal evrcla evrlca evrlac evarcl evarlc evacrl evaclr evalcr
evalrc evcarl evcalr evcral evcrla evclra evclar evlacr evlarc evlcar evlcra
evlrca evlrac ecrval ecrvla ecravl ecralv ecrlav ecrlva ecvral ecvrla ecvarl
ecvalr ecvlar ecvlra ecavrl ecavlr ecarvl ecarlv ecalrv ecalvr eclvar eclvra
eclavr eclarv eclrav eclrva elrvca elrvac elrcva elrcav elracv elravc elvrca
elvrac elvcra elvcar elvacr elvarc elcvra elcvar elcrva elcrav elcarv elcavr
elavcr elavrc elacvr elacrv elarcv elarvc larvec larvce larevc larecv larcev
larcve lavrec lavrce laverc lavecr lavcer lavcre laevrc laevcr laervc laercv
laecrv laecvr lacver lacvre lacevr lacerv lacrev lacrve lravec lravce lraevc
lraecv lracev lracve lrvaec lrvace lrveac lrveca lrvcea lrvcae lrevac lrevca
lreavc lreacv lrecav lrecva lrcvea lrcvae lrceva lrceav lrcaev lrcave lvraec
lvrace lvreac lvreca lvrcea lvrcae lvarec lvarce lvaerc lvaecr lvacer lvacre
lvearc lveacr lverac lverca lvecra lvecar lvcaer lvcare lvcear lvcera lvcrea
lvcrae lervac lervca leravc leracv lercav lercva levrac levrca levarc levacr
levcar levcra leavrc leavcr learvc learcv leacrv leacvr lecvar lecvra lecavr
lecarv lecrav lecrva lcrvea lcrvae lcreva lcreav lcraev lcrave lcvrea lcvrae
lcvera lcvear lcvaer lcvare lcevra lcevar lcerva lcerav lcearv lceavr lcaver
lcavre lcaevr lcaerv lcarev lcarve

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

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