No, I'm not being obtuse. I understand what you're saying; I believe that I understand why you think it's reasonable; and I totally reject the claim that it is not a backdoor. I don't care how many keys there are, and I don't care what the underlying technology is. If a group of people, no matter how many (other than the sender and receiver) can choose, by a designed feature of the encryption, to decrypt the communication, that's a backdoor, by definition.
And I assert that, no matter how carefully designed, a backdoor is always a bad idea.
Having two parties that have to agree is a mitigating feature. It makes it less bad. It doesn't make it good, though.
And I assert that, no matter how carefully designed, a backdoor is always a bad idea.
Having two parties that have to agree is a mitigating feature. It makes it less bad. It doesn't make it good, though.