[Cryptography] open questions in secure protocol design?

[Stephen Farrell]

On 31/05/15 15:00, Phillip Hallam-Baker wrote:
> Which is why I think that for future protocols we have to have TWO
> mandatory to implement algorithms, at least for not severely constrained
> devices.

I wonder if an "at most two" protocol restriction could work.

Probably not though, even if we designed protocols with a 1
or 2 bit algorithm id field I bet implementers on the receiver
side would still try out old stuff to see if it works even
after we'd all agreed to deprecate the last-but-one old/crap
thing.

S.