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: sortal
cipher variations:
tpsubm uqtvcn vruwdo wsvxep xtwyfq
yuxzgr zvyahs awzbit bxacju cybdkv
dzcelw eadfmx fbegny gcfhoz hdgipa
iehjqb jfikrc kgjlsd lhkmte milnuf
njmovg oknpwh ploqxi qmpryj rnqszk

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: sortal
Cipher: hligzo

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: sortal

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: sortal
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: sortal
Cipher: fbegny

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: sortal
Cipher: 344324441113

Extended Methods:
Method #1

Plaintext: sortal
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
s o r t a l 
3 4 2 4 1 1 
4 3 4 4 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: sortal
Cipher: sraotl

Read more ...
Method #3

Plaintext: sortal
method variations:
thtdan htdant tdanth
dantht anthtd nthtda

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: sortal

all 720 cipher variations:
sortal sortla soratl soralt sorlat sorlta sotral sotrla sotarl sotalr sotlar
sotlra soatrl soatlr soartl soarlt soalrt soaltr soltar soltra solatr solart
solrat solrta srotal srotla sroatl sroalt srolat srolta srtoal srtola srtaol
srtalo srtlao srtloa sratol sratlo sraotl sraolt sralot sralto srltao srltoa
srlato srlaot srloat srlota stroal strola straol stralo strlao strloa storal
storla stoarl stoalr stolar stolra staorl staolr starol starlo stalro stalor
stloar stlora stlaor stlaro stlrao stlroa sartol sartlo sarotl sarolt sarlot
sarlto satrol satrlo satorl satolr satlor satlro saotrl saotlr saortl saorlt
saolrt saoltr saltor saltro salotr salort salrot salrto slrtao slrtoa slrato
slraot slroat slrota sltrao sltroa sltaro sltaor sltoar sltora slatro slator
slarto slarot slaort slaotr slotar slotra sloatr sloart slorat slorta osrtal
osrtla osratl osralt osrlat osrlta ostral ostrla ostarl ostalr ostlar ostlra
osatrl osatlr osartl osarlt osalrt osaltr osltar osltra oslatr oslart oslrat
oslrta orstal orstla orsatl orsalt orslat orslta ortsal ortsla ortasl ortals
ortlas ortlsa oratsl oratls orastl oraslt oralst oralts orltas orltsa orlats
orlast orlsat orlsta otrsal otrsla otrasl otrals otrlas otrlsa otsral otsrla
otsarl otsalr otslar otslra otasrl otaslr otarsl otarls otalrs otalsr otlsar
otlsra otlasr otlars otlras otlrsa oartsl oartls oarstl oarslt oarlst oarlts
oatrsl oatrls oatsrl oatslr oatlsr oatlrs oastrl oastlr oasrtl oasrlt oaslrt
oasltr oaltsr oaltrs oalstr oalsrt oalrst oalrts olrtas olrtsa olrats olrast
olrsat olrsta oltras oltrsa oltars oltasr oltsar oltsra olatrs olatsr olarts
olarst olasrt olastr olstar olstra olsatr olsart olsrat olsrta rostal rostla
rosatl rosalt roslat roslta rotsal rotsla rotasl rotals rotlas rotlsa roatsl
roatls roastl roaslt roalst roalts roltas roltsa rolats rolast rolsat rolsta
rsotal rsotla rsoatl rsoalt rsolat rsolta rstoal rstola rstaol rstalo rstlao
rstloa rsatol rsatlo rsaotl rsaolt rsalot rsalto rsltao rsltoa rslato rslaot
rsloat rslota rtsoal rtsola rtsaol rtsalo rtslao rtsloa rtosal rtosla rtoasl
rtoals rtolas rtolsa rtaosl rtaols rtasol rtaslo rtalso rtalos rtloas rtlosa
rtlaos rtlaso rtlsao rtlsoa rastol rastlo rasotl rasolt raslot raslto ratsol
ratslo ratosl ratols ratlos ratlso raotsl raotls raostl raoslt raolst raolts
raltos raltso ralots ralost ralsot ralsto rlstao rlstoa rlsato rlsaot rlsoat
rlsota rltsao rltsoa rltaso rltaos rltoas rltosa rlatso rlatos rlasto rlasot
rlaost rlaots rlotas rlotsa rloats rloast rlosat rlosta torsal torsla torasl
torals torlas torlsa tosral tosrla tosarl tosalr toslar toslra toasrl toaslr
toarsl toarls toalrs toalsr tolsar tolsra tolasr tolars tolras tolrsa trosal
trosla troasl troals trolas trolsa trsoal trsola trsaol trsalo trslao trsloa
trasol traslo traosl traols tralos tralso trlsao trlsoa trlaso trlaos trloas
trlosa tsroal tsrola tsraol tsralo tsrlao tsrloa tsoral tsorla tsoarl tsoalr
tsolar tsolra tsaorl tsaolr tsarol tsarlo tsalro tsalor tsloar tslora tslaor
tslaro tslrao tslroa tarsol tarslo tarosl tarols tarlos tarlso tasrol tasrlo
tasorl tasolr taslor taslro taosrl taoslr taorsl taorls taolrs taolsr talsor
talsro talosr talors talros talrso tlrsao tlrsoa tlraso tlraos tlroas tlrosa
tlsrao tlsroa tlsaro tlsaor tlsoar tlsora tlasro tlasor tlarso tlaros tlaors
tlaosr tlosar tlosra tloasr tloars tloras tlorsa aortsl aortls aorstl aorslt
aorlst aorlts aotrsl aotrls aotsrl aotslr aotlsr aotlrs aostrl aostlr aosrtl
aosrlt aoslrt aosltr aoltsr aoltrs aolstr aolsrt aolrst aolrts arotsl arotls
arostl aroslt arolst arolts artosl artols artsol artslo artlso artlos arstol
arstlo arsotl arsolt arslot arslto arltso arltos arlsto arlsot arlost arlots
atrosl atrols atrsol atrslo atrlso atrlos atorsl atorls atosrl atoslr atolsr
atolrs atsorl atsolr atsrol atsrlo atslro atslor atlosr atlors atlsor atlsro
atlrso atlros asrtol asrtlo asrotl asrolt asrlot asrlto astrol astrlo astorl
astolr astlor astlro asotrl asotlr asortl asorlt asolrt asoltr asltor asltro
aslotr aslort aslrot aslrto alrtso alrtos alrsto alrsot alrost alrots altrso
altros altsro altsor altosr altors alstro alstor alsrto alsrot alsort alsotr
alotsr alotrs alostr alosrt alorst alorts lortas lortsa lorats lorast lorsat
lorsta lotras lotrsa lotars lotasr lotsar lotsra loatrs loatsr loarts loarst
loasrt loastr lostar lostra losatr losart losrat losrta lrotas lrotsa lroats
lroast lrosat lrosta lrtoas lrtosa lrtaos lrtaso lrtsao lrtsoa lratos lratso
lraots lraost lrasot lrasto lrstao lrstoa lrsato lrsaot lrsoat lrsota ltroas
ltrosa ltraos ltraso ltrsao ltrsoa ltoras ltorsa ltoars ltoasr ltosar ltosra
ltaors ltaosr ltaros ltarso ltasro ltasor ltsoar ltsora ltsaor ltsaro ltsrao
ltsroa lartos lartso larots larost larsot larsto latros latrso lators latosr
latsor latsro laotrs laotsr laorts laorst laosrt laostr lastor lastro lasotr
lasort lasrot lasrto lsrtao lsrtoa lsrato lsraot lsroat lsrota lstrao lstroa
lstaro lstaor lstoar lstora lsatro lsator lsarto lsarot lsaort lsaotr lsotar
lsotra lsoatr lsoart lsorat lsorta

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

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