unforgeable optical tokens?

[Barney Wolff]

On Sat, Sep 21, 2002 at 12:11:17AM +0000, David Wagner wrote:
> 
> I find the physical token a poor replacement for cryptography, when the
> goal is challenge-response authentication over a network.  In practice,
> you never really want just challenge-response authentication; you
> want to set up a secure, authenticated channel to the other party,
> which means you probably also need key distribution functionality.
> The physical token suggested here doesn't help with that at all.

Actually, it can.  The server can store challenge-responses in pairs,
then send N as the challenge and use the N+1 response (not returned)
as the key.

-- 
Barney Wolff
I'm available by contract or FT:  http://www.databus.com/bwresume.pdf

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