[Bitcoin-development] Address Expiration to Prevent Reuse

[Gregory Maxwell]

On Thu, Mar 26, 2015 at 8:38 PM, Tom Harding <tomh at thinlink.com> wrote:
> I addressed that by limiting the duplicate check to an X-block segment.  X
> is hard-coded in this simple scheme (X=144  => "1-day addresses").  You
> could picture a selectable expiration duration too.

If its to be heuristic in any case why not make it a client feature
instead of a consensus rule?

If someone wants to bypass anything they always can, thats what I mean
by "hide their payment under a rock"

E.g. I can take your pubkey, add G to it (adding 1 to the private
key), strip off the time limits, and send the funds.

"What do you mean I didn't pay you? I wrote a check. locked it in a
safe, and burred it in your back garden."

The answer to this can only be that payment is only tendered when its
made _exactly_ to the payee's specifications.

If someone violates the specifications all they're doing is destroying
coins. Nothing can stop people from destroying coins...

Which is why a simpler, safer, client enforced behavior is probably
preferable. Someone who wants to go hack their client to make a
payment that isn't according to the payee will have to live with the
results, esp. as we can't prevent that in a strong sense.