Cryptography in Mathematica

• IntegerDigits[n, b] computes the digits of the integer n in base b.
• FromDigits[list, b] constructs an integer from the digits in list using base b.
• FromCharacterCode[{n₁, n₂,...}] converts a list of numbers between 0 and 255 to an ASCII string.
• ToCharacterCode["text"] converts the given ASCII text to a list of numbers between 0 and 255.