At 08:09 PM 3/10/00 -0600, John Kelsey wrote:
>But there's a related engineering question: Does
>it make sense to build large systems in which there's no way
>for humans to overrule the actions of programs once they're
>set in motion?
...
>To use a more common example, I believe there were some cars
>(maybe experimental, I don't know) which would simply refuse
>to start the ignition until all passengers had their
>seatbelts on. There's no doubt that it's possible to design
>such a car. But you couldn't sell them without making it
>illegal to buy any other car, and users would flock to
>mechanics to have the feature removed in droves, regardless
>of the law.
It seems unnecessarily extreme to focus on (a) large systems and (b)
draconian enforcement of rules with obvious bad side-effects.
Point (a) is that small-scale irrevocable decisions abound, and we've
learned to live with them. On my computer, I issue irrevocable commands
hundreds of times per day. A good example is sending email, even though it
might have been possible to design the system to permit
revocation. Encrypting a file using a public key to which I don't hold the
private key (and expunging the original) is another irrevocable act that I
commonly perform. Submitting a document to a cryptological time-lock
system is no worse than this.
Point (b) is that if a 100% effective time-lock system were devised, I
would not expect that people would be required to use it (in the sense
suggested by the seatbelt interlock scenario above). Anybody who wanted to
defeat such a draconian requirement could just keep a copy somewhere else.
