Modulo Cipher

Modulo Cipher Encryption uses modular arithmetics and a sequence of numbers, characters must be converted into numbers, e.g. A=1, B=2, ... Z=26, but any numeric conversion (like the ASCII table) is fine.

Example: To crypt DCODE with the modulo 26, convert the text to numbers 4,3,15,4,5.

For each number to encrypt, calculate a random number which value is equal to the number to crypt.

Example: For \( 4 \), take \( 654 \), as \( 654 \equiv 4 \ mod 26 \)
For \( 3 \), take \( 965 \), as \( 965 \equiv 3 \ mod 26 \).
The encrypted message is 654,965,561,732,941 (many other cipher message are possible)

Decryption requires to know the value of the Modulo and to know the series of number to decrypt.

Example: The encrypted message is 654,965,561,732,941with the modulo 26.

For each number N, calculate the value of the remainder in the euclidean division of N by the modulo to get the plain number.

Example: The plain text is 4,3,15,4,5, that can be translate into DCODE with A=1, B=2, ...

The ciphered message is constituted of somehow large random numbers.