Caesar Cipher Using C++

By Anshuman Prakash

Caesar cipher is a basic substitution cipher that uses a key for encryption/decryption and it's implemented here using C++.

Caesar cipher is an encryption and decryption algorithm that is used to create ciphertexts and it comes under substitution ciphers. In caesar cipher, a key is used to substitute the character with another character and that is how whole plain text is encrypted.

Encryption is the process of encoding a message in such a way that it can’t be decoded by others without a proper key. A text message before encryption is known as plain text and an encrypted form of plain text is called ciphertext.

In Caesar cipher, encryption can be represented as : E(x) = (x+n) mod 26 ; Here 'x'  stands for the character being encrypted

Here ‘mod 26’ (also represented in code as ‘%26’) is done to make sure that the key substitutes the text characters by alphabets only.

For example : 40 mod 26 = 14

Also decryption can be represented as : D(x) = (x-n) mod 26

Caesar cipher is the most basic type of encryption and hence its security is disputed.