Posts Tagged ‘Symmetric Encryption’
In cryptography, Caesar cipher is one of the simplest encryption techniques. It is a substitution cipher in which each letter in the plaintext is replaced by a letter after a fixed number of positions down the alphabet. However, this applet shifts each character (letter, number of symbol) after a number of positions down the ASCII table. Caesar’s cipher is categorised as a symmetric encryption and the secret key in this case is the number of shifts!
- To encrypt, select the encode mode, number of shifts and click Run.
- You may encode a message multiple times.
- To Decrypt, select the Read the rest of this entry »

Have you seen a code similar to this before?
An interesting example from real life is the stone of James Leeson, who died in 1792. For a long time, the box-and-dot code at the top of the stone (Figure 1) remained a mystery for the public, but the secret was revealed as Meyer Berger explained in his NY Times column in the 1950s, it was finally decrypted. It says: “Remember death”. It was a Masonic cipher.

Figure 1: Stone of James Leeson 1
