On Mon, 25 Nov 1996 paul@fatbrain.demon.co.uk wrote:
Known-plaintext: Unbreakable, since the pad is never reused Chosen-plaintext: Unbreakable, ditto Adaptive-chosen-plaintext: Unbreakable, ditto
Correct but for a different reason.
No correct period, for the same reason. To paraphrase Gertrude Stein, an OTP is an OTP is an OTP.
Re-using the pad does render the security useless but the other reason is if we know part of the pad AND the ciphertext (and hence the plaintext) or part of the plaintext and the ciphertext and therefore the pad, We cannot solve the rest of the ciphertext as the pad is true random and the next bits are independent of all the previous ones so we cannot predict from what we have.
More dumbest information, from FAT BRAIN. If an OTP is used more than once, it is not an OTP by definition. Plaintext xor Plaintext, even in derivative forms. Like so much of his dribble, that paragraph contains some words but I challenge anyone to tell us what it means. It simply does not say anything which translates into anything meaningful. Frequently, you fill in some, and maybe even all of the plaintext, if you have part of the plain text, for example if you have the partial signature of a message emanating from the White House of: Wi Jef on You might reasonably conclude that the missing characters could be filled in to be: William Jefferson Clinton Two plaintexts xored together can reveal much more than you might think. With Kindest regards, Don Wood