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: dehaan
cipher variations:
efibbo fgjccp ghkddq hileer ijmffs
jknggt klohhu lmpiiv mnqjjw norkkx
opslly pqtmmz qrunna rsvoob stwppc
tuxqqd uvyrre vwzssf wxattg xybuuh
yzcvvi zadwwj abexxk bcfyyl cdgzzm

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: dehaan
Cipher: wvszzm

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: dehaan

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: dehaan
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: dehaan
Cipher: qrunna

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: dehaan
Cipher: 415132111133

Extended Methods:
Method #1

Plaintext: dehaan
method variations:

Method #2
Bifid cipher
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
d e h a a n 
4 5 3 1 1 3 
1 1 2 1 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: dehaan
Cipher: yclabl

Read more ...
Method #3

Plaintext: dehaan
method variations:
vlbals lbalsv balsvl
alsvlb lsvlba svlbal

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: dehaan

all 720 cipher variations:
dehaan dehana dehaan dehana dehnaa dehnaa deahan deahna deaahn deaanh deanah
deanha deaahn deaanh deahan deahna deanha deanah denaah denaha denaah denaha
denhaa denhaa dheaan dheana dheaan dheana dhenaa dhenaa dhaean dhaena dhaaen
dhaane dhanae dhanea dhaaen dhaane dhaean dhaena dhanea dhanae dhnaae dhnaea
dhnaae dhnaea dhneaa dhneaa dahean dahena dahaen dahane dahnae dahnea daehan
daehna daeahn daeanh daenah daenha daaehn daaenh daahen daahne daanhe daaneh
daneah daneha danaeh danahe danhae danhea dahaen dahane dahean dahena dahnea
dahnae daahen daahne daaehn daaenh daaneh daanhe daeahn daeanh daehan daehna
daenha daenah danaeh danahe daneah daneha danhea danhae dnhaae dnhaea dnhaae
dnhaea dnheaa dnheaa dnahae dnahea dnaahe dnaaeh dnaeah dnaeha dnaahe dnaaeh
dnahae dnahea dnaeha dnaeah dneaah dneaha dneaah dneaha dnehaa dnehaa edhaan
edhana edhaan edhana edhnaa edhnaa edahan edahna edaahn edaanh edanah edanha
edaahn edaanh edahan edahna edanha edanah ednaah ednaha ednaah ednaha ednhaa
ednhaa ehdaan ehdana ehdaan ehdana ehdnaa ehdnaa ehadan ehadna ehaadn ehaand
ehanad ehanda ehaadn ehaand ehadan ehadna ehanda ehanad ehnaad ehnada ehnaad
ehnada ehndaa ehndaa eahdan eahdna eahadn eahand eahnad eahnda eadhan eadhna
eadahn eadanh eadnah eadnha eaadhn eaadnh eaahdn eaahnd eaanhd eaandh eandah
eandha eanadh eanahd eanhad eanhda eahadn eahand eahdan eahdna eahnda eahnad
eaahdn eaahnd eaadhn eaadnh eaandh eaanhd eadahn eadanh eadhan eadhna eadnha
eadnah eanadh eanahd eandah eandha eanhda eanhad enhaad enhada enhaad enhada
enhdaa enhdaa enahad enahda enaahd enaadh enadah enadha enaahd enaadh enahad
enahda enadha enadah endaah endaha endaah endaha endhaa endhaa hedaan hedana
hedaan hedana hednaa hednaa headan headna heaadn heaand heanad heanda heaadn
heaand headan headna heanda heanad henaad henada henaad henada hendaa hendaa
hdeaan hdeana hdeaan hdeana hdenaa hdenaa hdaean hdaena hdaaen hdaane hdanae
hdanea hdaaen hdaane hdaean hdaena hdanea hdanae hdnaae hdnaea hdnaae hdnaea
hdneaa hdneaa hadean hadena hadaen hadane hadnae hadnea haedan haedna haeadn
haeand haenad haenda haaedn haaend haaden haadne haande haaned hanead haneda
hanaed hanade handae handea hadaen hadane hadean hadena hadnea hadnae haaden
haadne haaedn haaend haaned haande haeadn haeand haedan haedna haenda haenad
hanaed hanade hanead haneda handea handae hndaae hndaea hndaae hndaea hndeaa
hndeaa hnadae hnadea hnaade hnaaed hnaead hnaeda hnaade hnaaed hnadae hnadea
hnaeda hnaead hneaad hneada hneaad hneada hnedaa hnedaa aehdan aehdna aehadn
aehand aehnad aehnda aedhan aedhna aedahn aedanh aednah aednha aeadhn aeadnh
aeahdn aeahnd aeanhd aeandh aendah aendha aenadh aenahd aenhad aenhda ahedan
ahedna aheadn aheand ahenad ahenda ahdean ahdena ahdaen ahdane ahdnae ahdnea
ahaden ahadne ahaedn ahaend ahaned ahande ahndae ahndea ahnade ahnaed ahnead
ahneda adhean adhena adhaen adhane adhnae adhnea adehan adehna adeahn adeanh
adenah adenha adaehn adaenh adahen adahne adanhe adaneh adneah adneha adnaeh
adnahe adnhae adnhea aahden aahdne aahedn aahend aahned aahnde aadhen aadhne
aadehn aadenh aadneh aadnhe aaedhn aaednh aaehdn aaehnd aaenhd aaendh aandeh
aandhe aanedh aanehd aanhed aanhde anhdae anhdea anhade anhaed anhead anheda
andhae andhea andahe andaeh andeah andeha anadhe anadeh anahde anahed anaehd
anaedh anedah anedha aneadh aneahd anehad anehda aehadn aehand aehdan aehdna
aehnda aehnad aeahdn aeahnd aeadhn aeadnh aeandh aeanhd aedahn aedanh aedhan
aedhna aednha aednah aenadh aenahd aendah aendha aenhda aenhad aheadn aheand
ahedan ahedna ahenda ahenad ahaedn ahaend ahaden ahadne ahande ahaned ahdaen
ahdane ahdean ahdena ahdnea ahdnae ahnade ahnaed ahndae ahndea ahneda ahnead
aahedn aahend aahden aahdne aahnde aahned aaehdn aaehnd aaedhn aaednh aaendh
aaenhd aadehn aadenh aadhen aadhne aadnhe aadneh aanedh aanehd aandeh aandhe
aanhde aanhed adhaen adhane adhean adhena adhnea adhnae adahen adahne adaehn
adaenh adaneh adanhe adeahn adeanh adehan adehna adenha adenah adnaeh adnahe
adneah adneha adnhea adnhae anhade anhaed anhdae anhdea anheda anhead anahde
anahed anadhe anadeh anaedh anaehd andahe andaeh andhae andhea andeha andeah
aneadh aneahd anedah anedha anehda anehad nehaad nehada nehaad nehada nehdaa
nehdaa neahad neahda neaahd neaadh neadah neadha neaahd neaadh neahad neahda
neadha neadah nedaah nedaha nedaah nedaha nedhaa nedhaa nheaad nheada nheaad
nheada nhedaa nhedaa nhaead nhaeda nhaaed nhaade nhadae nhadea nhaaed nhaade
nhaead nhaeda nhadea nhadae nhdaae nhdaea nhdaae nhdaea nhdeaa nhdeaa nahead
naheda nahaed nahade nahdae nahdea naehad naehda naeahd naeadh naedah naedha
naaehd naaedh naahed naahde naadhe naadeh nadeah nadeha nadaeh nadahe nadhae
nadhea nahaed nahade nahead naheda nahdea nahdae naahed naahde naaehd naaedh
naadeh naadhe naeahd naeadh naehad naehda naedha naedah nadaeh nadahe nadeah
nadeha nadhea nadhae ndhaae ndhaea ndhaae ndhaea ndheaa ndheaa ndahae ndahea
ndaahe ndaaeh ndaeah ndaeha ndaahe ndaaeh ndahae ndahea ndaeha ndaeah ndeaah
ndeaha ndeaah ndeaha ndehaa ndehaa

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

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