Hmm, as far as I'm aware, you can't do cryptanalysis on 2 characters. Marxos A factoid which is irrelevant in this context. If you only wanted to encrypt two characters, once, you could use ROT-13 and nobody would be the wiser.
ot a factoid. I'm making the claim that you can't decrypt it. I don't want to do the proof, because I can deduce it, with Pretty Good Certainty (TM). If you have a key approx 1/2 the size of the text, AND you do NOT know the length of the key, you have essentially two characters to do cryptanalysis. Now the key may be a small enough dictionary to do more analysis, and since you know that each set of the same modulus is using the same key character, but without knowing the length of the key, it's going to be next to impossible. There are many false leads (key-text combinations which result in what seems like valid plaintext) and the search space becomes too large.>
You've added the silly limiting condition that you are referring only to messages with two characters, which has virtually nothing to do with most messages sent by OTP.
No, I'm saying if the key is about half the text -- THAT ALL YOU GET TO ANALYZE.
And, I observe if indeed you are only referring to two character messages, then the One Time Pad with half that number of characters, ONE character, amounts to the same thing as ROT-13, except where the number "13" is allowed to vary between 0 and 25.
Perhaps you didn't see my followup, but you still don't get it: there are many false positives: decrypts that lead to semi-valid texts WHICH YOU HAVE NO WAY TO DETERMINE VALIDITY (given no futher data). You don't know if the key is 1 char or 2 characters, so there is a complete set of valid decrypts which may or may not be the original and you have no way to determine that. marxos