AFAICT, it is UNBREAKABLE if the keysize is at least half the size ofyour plaintext.My understanding is that the keysize ought to be as long as the message tobe encrypted.
Well if they don't know the key length, then using somewhere between
1/3 and 2/3 should make it unbreakable.
And yes, it is unbreakable... UNLESS you try to reuse the keys!!!
Hmm, but THEY don't know if you re-used them. So it would take how
many ciphertexts messages to figure that out?
Marxos