It wasn't just a matter of one "back door" but a matter of knowing that (1) people usually use codes incorrectly or screw up the key management and (2) if you give them a little help the key management will always be screwed up.
It wasn't just a matter of one "back door" but a matter of knowing that (1) people usually use codes incorrectly or screw up the key management and (2) if you give them a little help the key management will always be screwed up.