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: sumati
cipher variations:
tvnbuj uwocvk vxpdwl wyqexm xzrfyn
yasgzo zbthap acuibq bdvjcr cewkds
dfxlet egymfu fhzngv giaohw hjbpix
ikcqjy jldrkz kmesla lnftmb mogunc
nphvod oqiwpe prjxqf qskyrg rtlzsh

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: sumati
Cipher: hfnzgr

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: sumati

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: sumati
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: sumati
Cipher: fhzngv

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: sumati
Cipher: 345423114442

Extended Methods:
Method #1

Plaintext: sumati
method variations:

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

Read more ...
Method #3

Plaintext: sumati
method variations:
yicqtm icqtmy cqtmyi
qtmyic tmyicq myicqt

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: sumati

all 720 cipher variations:
sumati sumait sumtai sumtia sumita sumiat suamti suamit suatmi suatim suaitm
suaimt sutami sutaim sutmai sutmia sutima sutiam suiatm suiamt suitam suitma
suimta suimat smuati smuait smutai smutia smuita smuiat smauti smauit smatui
smatiu smaitu smaiut smtaui smtaiu smtuai smtuia smtiua smtiau smiatu smiaut
smitau smitua smiuta smiuat samuti samuit samtui samtiu samitu samiut saumti
saumit sautmi sautim sauitm sauimt satumi satuim satmui satmiu satimu satium
saiutm saiumt saitum saitmu saimtu saimut stmaui stmaiu stmuai stmuia stmiua
stmiau stamui stamiu staumi stauim staium staimu stuami stuaim stumai stumia
stuima stuiam stiaum stiamu stiuam stiuma stimua stimau simatu simaut simtau
simtua simuta simuat siamtu siamut siatmu siatum siautm siaumt sitamu sitaum
sitmau sitmua situma situam siuatm siuamt siutam siutma siumta siumat usmati
usmait usmtai usmtia usmita usmiat usamti usamit usatmi usatim usaitm usaimt
ustami ustaim ustmai ustmia ustima ustiam usiatm usiamt usitam usitma usimta
usimat umsati umsait umstai umstia umsita umsiat umasti umasit umatsi umatis
umaits umaist umtasi umtais umtsai umtsia umtisa umtias umiats umiast umitas
umitsa umista umisat uamsti uamsit uamtsi uamtis uamits uamist uasmti uasmit
uastmi uastim uasitm uasimt uatsmi uatsim uatmsi uatmis uatims uatism uaistm
uaismt uaitsm uaitms uaimts uaimst utmasi utmais utmsai utmsia utmisa utmias
utamsi utamis utasmi utasim utaism utaims utsami utsaim utsmai utsmia utsima
utsiam utiasm utiams utisam utisma utimsa utimas uimats uimast uimtas uimtsa
uimsta uimsat uiamts uiamst uiatms uiatsm uiastm uiasmt uitams uitasm uitmas
uitmsa uitsma uitsam uisatm uisamt uistam uistma uismta uismat musati musait
mustai mustia musita musiat muasti muasit muatsi muatis muaits muaist mutasi
mutais mutsai mutsia mutisa mutias muiats muiast muitas muitsa muista muisat
msuati msuait msutai msutia msuita msuiat msauti msauit msatui msatiu msaitu
msaiut mstaui mstaiu mstuai mstuia mstiua mstiau msiatu msiaut msitau msitua
msiuta msiuat masuti masuit mastui mastiu masitu masiut mausti mausit mautsi
mautis mauits mauist matusi matuis matsui matsiu matisu matius maiuts maiust
maitus maitsu maistu maisut mtsaui mtsaiu mtsuai mtsuia mtsiua mtsiau mtasui
mtasiu mtausi mtauis mtaius mtaisu mtuasi mtuais mtusai mtusia mtuisa mtuias
mtiaus mtiasu mtiuas mtiusa mtisua mtisau misatu misaut mistau mistua misuta
misuat miastu miasut miatsu miatus miauts miaust mitasu mitaus mitsau mitsua
mitusa mituas miuats miuast miutas miutsa miusta miusat aumsti aumsit aumtsi
aumtis aumits aumist ausmti ausmit austmi austim ausitm ausimt autsmi autsim
autmsi autmis autims autism auistm auismt auitsm auitms auimts auimst amusti
amusit amutsi amutis amuits amuist amsuti amsuit amstui amstiu amsitu amsiut
amtsui amtsiu amtusi amtuis amtius amtisu amistu amisut amitsu amitus amiuts
amiust asmuti asmuit asmtui asmtiu asmitu asmiut asumti asumit asutmi asutim
asuitm asuimt astumi astuim astmui astmiu astimu astium asiutm asiumt asitum
asitmu asimtu asimut atmsui atmsiu atmusi atmuis atmius atmisu atsmui atsmiu
atsumi atsuim atsium atsimu atusmi atusim atumsi atumis atuims atuism atisum
atismu atiusm atiums atimus atimsu aimstu aimsut aimtsu aimtus aimuts aimust
aismtu aismut aistmu aistum aisutm aisumt aitsmu aitsum aitmsu aitmus aitums
aitusm aiustm aiusmt aiutsm aiutms aiumts aiumst tumasi tumais tumsai tumsia
tumisa tumias tuamsi tuamis tuasmi tuasim tuaism tuaims tusami tusaim tusmai
tusmia tusima tusiam tuiasm tuiams tuisam tuisma tuimsa tuimas tmuasi tmuais
tmusai tmusia tmuisa tmuias tmausi tmauis tmasui tmasiu tmaisu tmaius tmsaui
tmsaiu tmsuai tmsuia tmsiua tmsiau tmiasu tmiaus tmisau tmisua tmiusa tmiuas
tamusi tamuis tamsui tamsiu tamisu tamius taumsi taumis tausmi tausim tauism
tauims tasumi tasuim tasmui tasmiu tasimu tasium taiusm taiums taisum taismu
taimsu taimus tsmaui tsmaiu tsmuai tsmuia tsmiua tsmiau tsamui tsamiu tsaumi
tsauim tsaium tsaimu tsuami tsuaim tsumai tsumia tsuima tsuiam tsiaum tsiamu
tsiuam tsiuma tsimua tsimau timasu timaus timsau timsua timusa timuas tiamsu
tiamus tiasmu tiasum tiausm tiaums tisamu tisaum tismau tismua tisuma tisuam
tiuasm tiuams tiusam tiusma tiumsa tiumas iumats iumast iumtas iumtsa iumsta
iumsat iuamts iuamst iuatms iuatsm iuastm iuasmt iutams iutasm iutmas iutmsa
iutsma iutsam iusatm iusamt iustam iustma iusmta iusmat imuats imuast imutas
imutsa imusta imusat imauts imaust imatus imatsu imastu imasut imtaus imtasu
imtuas imtusa imtsua imtsau imsatu imsaut imstau imstua imsuta imsuat iamuts
iamust iamtus iamtsu iamstu iamsut iaumts iaumst iautms iautsm iaustm iausmt
iatums iatusm iatmus iatmsu iatsmu iatsum iasutm iasumt iastum iastmu iasmtu
iasmut itmaus itmasu itmuas itmusa itmsua itmsau itamus itamsu itaums itausm
itasum itasmu ituams ituasm itumas itumsa itusma itusam itsaum itsamu itsuam
itsuma itsmua itsmau ismatu ismaut ismtau ismtua ismuta ismuat isamtu isamut
isatmu isatum isautm isaumt istamu istaum istmau istmua istuma istuam isuatm
isuamt isutam isutma isumta isumat

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

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