Caesar Cipher is one of the simplest and most widely known encryption techniques in Cryptography. It is also known as Caesar’s cipher, the shift cipher, Caesar’s code or Caesar shift.

It is a kind of substitution cipher where each letter in a plaintext (the plain message) is replaced by another letter as ciphertext (Encrypted message), hence the substitution cipher. The

substitution is carried out by replacing a plaintext letter by a letter three places further down the alphabet (the alphabet set from A to Z).

For example,

Plaintext: The ciphertext for A would be D.  ( Since, if A=0th position, B=1st shift, C=2nd shift, D=3rd shift)

Similarly for all the alphabets, the ciphertext would be:

Plaintext:     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

                      |      |     |         |     |     |     |    |    |    |    |     |      |    |     |     |     |    |    |      |     |      |     |    |     | 

Ciphertext:  D    E    F   G  H   I    J    K    L  M  N  O   P    Q   R   S   T    U   V  W   X   Y   Z    A   B   C