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: lignone
cipher variations:
mjhopof
nkipqpg
oljqrqh
pmkrsri
qnlstsj
romtutk
spnuvul
tqovwvm
urpwxwn
vsqxyxo
wtryzyp
xuszazq
yvtabar
zwubcbs
axvcdct
bywdedu
czxefev
dayfgfw
ebzghgx
fcahihy
gdbijiz
hecjkja
ifdklkb
jgelmlc
khfmnmd
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:
lignone
Cipher:
ortmlmv
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:
lignone
Cipher:
ABABA ABAAA AABBA ABBAA ABBAB ABBAA AABAA
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: lignone
cipher variations:
mjhopof
iztoron
epfotov
afrovod
wvdoxol
slpozot
krnodoj
ghzofor
cxlohoz
ynxojoh
udjolop
qtvonox
nkipqpg
jaupspo
fqgpupw
bgspwpe
xwepypm
tmqpapu
lsopepk
hiapgps
dympipa
zoypkpi
vekpmpq
ruwpopy
oljqrqh
kbvqtqp
grhqvqx
chtqxqf
yxfqzqn
unrqbqv
mtpqfql
ijbqhqt
eznqjqb
apzqlqj
wflqnqr
svxqpqz
pmkrsri
lcwrurq
hsirwry
diuryrg
zygraro
vosrcrw
nuqrgrm
jkcriru
faorkrc
bqarmrk
xgmrors
twyrqra
qnlstsj
mdxsvsr
itjsxsz
ejvszsh
azhsbsp
wptsdsx
ovrshsn
kldsjsv
gbpslsd
crbsnsl
yhnspst
uxzsrsb
romtutk
neytwts
juktyta
fkwtati
baitctq
xqutety
pwstito
lmetktw
hcqtmte
dsctotm
ziotqtu
vyatstc
spnuvul
ofzuxut
kvluzub
glxubuj
cbjudur
yrvufuz
qxtujup
mnfulux
idrunuf
etdupun
ajpuruv
wzbutud
tqovwvm
pgavyvu
lwmvavc
hmyvcvk
dckvevs
zswvgva
ryuvkvq
nogvmvy
jesvovg
fuevqvo
bkqvsvw
xacvuve
urpwxwn
qhbwzwv
mxnwbwd
inzwdwl
edlwfwt
atxwhwb
szvwlwr
ophwnwz
kftwpwh
gvfwrwp
clrwtwx
ybdwvwf
vsqxyxo
ricxaxw
nyoxcxe
joaxexm
femxgxu
buyxixc
tawxmxs
pqixoxa
lguxqxi
hwgxsxq
dmsxuxy
zcexwxg
wtryzyp
sjdybyx
ozpydyf
kpbyfyn
gfnyhyv
cvzyjyd
ubxynyt
qrjypyb
mhvyryj
ixhytyr
entyvyz
adfyxyh
xuszazq
tkezczy
paqzezg
lqczgzo
hgozizw
dwazkze
vcyzozu
rskzqzc
niwzszk
jyizuzs
fouzwza
begzyzi
yvtabar
ulfadaz
qbrafah
mrdahap
ihpajax
exbalaf
wdzapav
stlarad
ojxatal
kzjavat
gpvaxab
cfhazaj
zwubcbs
vmgbeba
rcsbgbi
nsebibq
jiqbkby
fycbmbg
xeabqbw
tumbsbe
pkybubm
lakbwbu
hqwbybc
dgibabk
axvcdct
wnhcfcb
sdtchcj
otfcjcr
kjrclcz
gzdcnch
yfbcrcx
uvnctcf
qlzcvcn
mblcxcv
irxczcd
ehjcbcl
bywdedu
xoidgdc
teudidk
pugdkds
lksdmda
haedodi
zgcdsdy
vwodudg
rmadwdo
ncmdydw
jsydade
fikdcdm
czxefev
ypjehed
ufvejel
qvhelet
mlteneb
ibfepej
ahdetez
wxpeveh
snbexep
odnezex
ktzebef
gjleden
dayfgfw
zqkfife
vgwfkfm
rwifmfu
nmufofc
jcgfqfk
biefufa
xyqfwfi
tocfyfq
peofafy
luafcfg
hkmfefo
ebzghgx
arlgjgf
whxglgn
sxjgngv
onvgpgd
kdhgrgl
cjfgvgb
yzrgxgj
updgzgr
qfpgbgz
mvbgdgh
ilngfgp
fcahihy
bsmhkhg
xiyhmho
tykhohw
powhqhe
leihshm
dkghwhc
zashyhk
vqehahs
rgqhcha
nwchehi
jmohghq
gdbijiz
ctnilih
yjzinip
uzlipix
qpxirif
mfjitin
elhixid
abtizil
wrfibit
shridib
oxdifij
knpihir
hecjkja
duojmji
zkajojq
vamjqjy
rqyjsjg
ngkjujo
fmijyje
bcujajm
xsgjcju
tisjejc
pyejgjk
loqjijs
ifdklkb
evpknkj
albkpkr
wbnkrkz
srzktkh
ohlkvkp
gnjkzkf
cdvkbkn
ythkdkv
ujtkfkd
qzfkhkl
mprkjkt
jgelmlc
fwqlolk
bmclqls
xcolsla
tsaluli
pimlwlq
hoklalg
dewlclo
zuilelw
vkulgle
raglilm
nqslklu
khfmnmd
gxrmpml
cndmrmt
ydpmtmb
utbmvmj
qjnmxmr
iplmbmh
efxmdmp
avjmfmx
wlvmhmf
sbhmjmn
ortmlmv
lignone
hysnqnm
doensnu
zeqnunc
vucnwnk
rkonyns
jqmncni
fgynenq
bwkngny
xmwning
tcinkno
psunmnw
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:
lignone
Cipher:
yvtabar
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.
A
B
C
D
E
F
G
H
I/J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Basic Form:
Plain:
lignone
Cipher:
Extended Methods: Method #1
Plaintext: lignone
method variations:
qomstsk
vtrxyxp
aywcdcu
fdbhihz
Method #2 Bifid cipher The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
l i g n o n e
1 4 2 3 4 3 5
3 2 2 3 3 3 1
They are then read out in rows: 14234353223331 Then divided up into pairs again, and the pairs turned back into letters using the square:
Plain:
lignone
Cipher:
qmopgnc
Read more ... Method #3
Plaintext: lignone
method variations:
sgmsnxa
gmsnxas
msnxasg
snxasgm
nxasgms
xasgmsn
asgmsnx
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: lignone