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: prunty
cipher variations:
qsvouz rtwpva suxqwb tvyrxc uwzsyd
vxatze wybuaf xzcvbg yadwch zbexdi
acfyej bdgzfk cehagl dfibhm egjcin
fhkdjo gilekp hjmflq ikngmr jlohns
kmpiot lnqjpu morkqv npslrw oqtmsx

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: prunty
Cipher: kifmgb

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: prunty

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: prunty
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: prunty
Cipher: cehagl

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: prunty
Cipher: 532454334445

Extended Methods:
Method #1

Plaintext: prunty
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
p r u n t y 
5 2 5 3 4 4 
3 4 4 3 4 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: prunty
Cipher: kptsoy

Read more ...
Method #3

Plaintext: prunty
method variations:
hyostz yostzh ostzhy
stzhyo tzhyos zhyost

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: prunty

all 720 cipher variations:
prunty prunyt prutny prutyn pruytn pruynt prnuty prnuyt prntuy prntyu prnytu
prnyut prtnuy prtnyu prtuny prtuyn prtyun prtynu pryntu prynut prytnu prytun
pryutn pryunt purnty purnyt purtny purtyn purytn purynt punrty punryt puntry
puntyr punytr punyrt putnry putnyr putrny putryn putyrn putynr puyntr puynrt
puytnr puytrn puyrtn puyrnt pnurty pnuryt pnutry pnutyr pnuytr pnuyrt pnruty
pnruyt pnrtuy pnrtyu pnrytu pnryut pntruy pntryu pntury pntuyr pntyur pntyru
pnyrtu pnyrut pnytru pnytur pnyutr pnyurt ptunry ptunyr pturny pturyn ptuyrn
ptuynr ptnury ptnuyr ptnruy ptnryu ptnyru ptnyur ptrnuy ptrnyu ptruny ptruyn
ptryun ptrynu ptynru ptynur ptyrnu ptyrun ptyurn ptyunr pyuntr pyunrt pyutnr
pyutrn pyurtn pyurnt pynutr pynurt pyntur pyntru pynrtu pynrut pytnur pytnru
pytunr pyturn pytrun pytrnu pyrntu pyrnut pyrtnu pyrtun pyrutn pyrunt rpunty
rpunyt rputny rputyn rpuytn rpuynt rpnuty rpnuyt rpntuy rpntyu rpnytu rpnyut
rptnuy rptnyu rptuny rptuyn rptyun rptynu rpyntu rpynut rpytnu rpytun rpyutn
rpyunt rupnty rupnyt ruptny ruptyn rupytn rupynt runpty runpyt runtpy runtyp
runytp runypt rutnpy rutnyp rutpny rutpyn rutypn rutynp ruyntp ruynpt ruytnp
ruytpn ruyptn ruypnt rnupty rnupyt rnutpy rnutyp rnuytp rnuypt rnputy rnpuyt
rnptuy rnptyu rnpytu rnpyut rntpuy rntpyu rntupy rntuyp rntyup rntypu rnyptu
rnyput rnytpu rnytup rnyutp rnyupt rtunpy rtunyp rtupny rtupyn rtuypn rtuynp
rtnupy rtnuyp rtnpuy rtnpyu rtnypu rtnyup rtpnuy rtpnyu rtpuny rtpuyn rtpyun
rtpynu rtynpu rtynup rtypnu rtypun rtyupn rtyunp ryuntp ryunpt ryutnp ryutpn
ryuptn ryupnt rynutp rynupt ryntup ryntpu rynptu rynput rytnup rytnpu rytunp
rytupn rytpun rytpnu rypntu rypnut ryptnu ryptun ryputn rypunt urpnty urpnyt
urptny urptyn urpytn urpynt urnpty urnpyt urntpy urntyp urnytp urnypt urtnpy
urtnyp urtpny urtpyn urtypn urtynp uryntp urynpt urytnp urytpn uryptn urypnt
uprnty uprnyt uprtny uprtyn uprytn uprynt upnrty upnryt upntry upntyr upnytr
upnyrt uptnry uptnyr uptrny uptryn uptyrn uptynr upyntr upynrt upytnr upytrn
upyrtn upyrnt unprty unpryt unptry unptyr unpytr unpyrt unrpty unrpyt unrtpy
unrtyp unrytp unrypt untrpy untryp untpry untpyr untypr untyrp unyrtp unyrpt
unytrp unytpr unyptr unyprt utpnry utpnyr utprny utpryn utpyrn utpynr utnpry
utnpyr utnrpy utnryp utnyrp utnypr utrnpy utrnyp utrpny utrpyn utrypn utrynp
utynrp utynpr utyrnp utyrpn utyprn utypnr uypntr uypnrt uyptnr uyptrn uyprtn
uyprnt uynptr uynprt uyntpr uyntrp uynrtp uynrpt uytnpr uytnrp uytpnr uytprn
uytrpn uytrnp uyrntp uyrnpt uyrtnp uyrtpn uyrptn uyrpnt nrupty nrupyt nrutpy
nrutyp nruytp nruypt nrputy nrpuyt nrptuy nrptyu nrpytu nrpyut nrtpuy nrtpyu
nrtupy nrtuyp nrtyup nrtypu nryptu nryput nrytpu nrytup nryutp nryupt nurpty
nurpyt nurtpy nurtyp nurytp nurypt nuprty nupryt nuptry nuptyr nupytr nupyrt
nutpry nutpyr nutrpy nutryp nutyrp nutypr nuyptr nuyprt nuytpr nuytrp nuyrtp
nuyrpt npurty npuryt nputry nputyr npuytr npuyrt npruty npruyt nprtuy nprtyu
nprytu npryut nptruy nptryu nptury nptuyr nptyur nptyru npyrtu npyrut npytru
npytur npyutr npyurt ntupry ntupyr nturpy nturyp ntuyrp ntuypr ntpury ntpuyr
ntpruy ntpryu ntpyru ntpyur ntrpuy ntrpyu ntrupy ntruyp ntryup ntrypu ntypru
ntypur ntyrpu ntyrup ntyurp ntyupr nyuptr nyuprt nyutpr nyutrp nyurtp nyurpt
nyputr nypurt nyptur nyptru nyprtu nyprut nytpur nytpru nytupr nyturp nytrup
nytrpu nyrptu nyrput nyrtpu nyrtup nyrutp nyrupt trunpy trunyp trupny trupyn
truypn truynp trnupy trnuyp trnpuy trnpyu trnypu trnyup trpnuy trpnyu trpuny
trpuyn trpyun trpynu trynpu trynup trypnu trypun tryupn tryunp turnpy turnyp
turpny turpyn turypn turynp tunrpy tunryp tunpry tunpyr tunypr tunyrp tupnry
tupnyr tuprny tupryn tupyrn tupynr tuynpr tuynrp tuypnr tuyprn tuyrpn tuyrnp
tnurpy tnuryp tnupry tnupyr tnuypr tnuyrp tnrupy tnruyp tnrpuy tnrpyu tnrypu
tnryup tnpruy tnpryu tnpury tnpuyr tnpyur tnpyru tnyrpu tnyrup tnypru tnypur
tnyupr tnyurp tpunry tpunyr tpurny tpuryn tpuyrn tpuynr tpnury tpnuyr tpnruy
tpnryu tpnyru tpnyur tprnuy tprnyu tpruny tpruyn tpryun tprynu tpynru tpynur
tpyrnu tpyrun tpyurn tpyunr tyunpr tyunrp tyupnr tyuprn tyurpn tyurnp tynupr
tynurp tynpur tynpru tynrpu tynrup typnur typnru typunr typurn typrun typrnu
tyrnpu tyrnup tyrpnu tyrpun tyrupn tyrunp yruntp yrunpt yrutnp yrutpn yruptn
yrupnt yrnutp yrnupt yrntup yrntpu yrnptu yrnput yrtnup yrtnpu yrtunp yrtupn
yrtpun yrtpnu yrpntu yrpnut yrptnu yrptun yrputn yrpunt yurntp yurnpt yurtnp
yurtpn yurptn yurpnt yunrtp yunrpt yuntrp yuntpr yunptr yunprt yutnrp yutnpr
yutrnp yutrpn yutprn yutpnr yupntr yupnrt yuptnr yuptrn yuprtn yuprnt ynurtp
ynurpt ynutrp ynutpr ynuptr ynuprt ynrutp ynrupt ynrtup ynrtpu ynrptu ynrput
yntrup yntrpu ynturp yntupr yntpur yntpru ynprtu ynprut ynptru ynptur ynputr
ynpurt ytunrp ytunpr yturnp yturpn ytuprn ytupnr ytnurp ytnupr ytnrup ytnrpu
ytnpru ytnpur ytrnup ytrnpu ytrunp ytrupn ytrpun ytrpnu ytpnru ytpnur ytprnu
ytprun ytpurn ytpunr ypuntr ypunrt yputnr yputrn ypurtn ypurnt ypnutr ypnurt
ypntur ypntru ypnrtu ypnrut yptnur yptnru yptunr ypturn yptrun yptrnu yprntu
yprnut yprtnu yprtun yprutn yprunt

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

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