One Time Pad

It is said that the one-time pad is the best cipher anywhere. It is uncrackable as long as you keep the messages short, use shorthand and abbreviations, remove unnecessary letters, never reuse a pad, and have a good enough random source for data.

This implementation will take the letters (and letters only) from the pad and encrypt the letters from your message. It leaves alone spaces, newlines (enters / returns), punctuation, numbers, and anything else that isn’t A-Z. Make sure that your pad is at least as long as your message; otherwise, your message will not be encoded.