Substitution Cipher - Definition

Substitution Cipher

Wiki says: In cryptography, a substitution cipher is a method of encryption by which units of plaintext are substituted with ciphertext according to a regular system; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing an inverse substitution.

Encoding / Decoding

  • Encoding and decoding of text encrypted by simple substitution cipher.
Simple Substitution Cipher

Wiki says: Substitution over a single letter - simple substitution - can be demonstrated by writing out the alphabet in some order to represent the substitution. This is termed a substitution alphabet. The cipher alphabet may be shifted or reversed (creating the Caesar and Atbash ciphers, respectively) or scrambled in a more complex fashion, in which case it is called a mixed alphabet or deranged alphabet. Traditionally, mixed alphabets are created by first writing out a keyword, then all the remaining letters.

Julian Caesar Cipher

Wiki says: In cryptography, a Caesar cipher, also known as a Caesar shift cipher or shift cipher, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions further down the alphabet. For example, with a shift of 3, A would be replaced by D, B would become E, and so on. The method is named after Julius Caesar, who used it to communicate with his generals.


When it comes to your email, there should be no substitution for privacy in your account. With your email on a microsoft exchange server, you should have great protection of your email account. A lot of email hosting sites don't offer the best protection. Exchange 2007 is one of the most common email systems out. YOu can also run many different accounts with exchange email outsourcing. You can also try coldfusion hosting.

Relative frequencies of letters

Relative frequencies of letters in english language

e 0.12702
t 0.09056
a 0.08167
o 0.07507
i 0.06966
n 0.06749
s 0.06327
h 0.06094
r 0.05987
d 0.04253
l 0.04025
c 0.02782
u 0.02758
m 0.02406
w 0.02360
f 0.02228
g 0.02015
y 0.01974
p 0.01929
b 0.01492
v 0.00978
k 0.00772
j 0.00153
x 0.00150
q 0.00095
z 0.00074

Substitution Cipher, Copyright Š 2005 by Andrej Probst, All rights reserved.
Portal | Tools | Matches | Hangman | Number Conversion | BMI | Geography Exams | Morse Code | Measurement | Vtipy a hlavolamy | Čítanie | Kuchárka | Logo | Max hra | Nákupné centrum | Športové centrum | Skratky | Spravodajstvo Mráčik | RSS katalóg | Twitter katalóg | Instagram na SK i CZ | Nameday calendar | To je trapas | Bankomaty na Slovensku | Bankomaty v České republice | Tvoj Lekár | Ponuky práce v zdravotníctve | Zdravotná poradňa | Tvůj lékař | Vyber školu | Kto hýbe Slovenskom | Kdo hýbe Českem | Palivové drevo | Tvoj Notár | Tvůj notář | Sudoku for Kids | Road for Kids | Pair for Kids | Hanoi for Kids | 15 for Kids | Grid for Kids | Colours for Kids | Pexeso | Logic | Einstein | Snake | 3 Wheels | Find 8