>
> Think cash is a stupid idea, and won't work in practice. You don't
> want to be trying to solve puzzles when you really just want to send
> your email or post messages.
There are only two ways I can think of to have a communications system
with a public address that isn't mechanically spammable:
1) Think Cash. BTW, I don't really agree that they wont work in practice,
you can make a puzzle that is trivial for a human but difficult for
a machine. Not just trivial, but even fairly non-intrusive.
2) Cryptographic permission based email. This would entail generating a
'credit' that you give to a person you want to email you. He/she can
perform a calculation with the credit and say the day/hour when the
email will be sent. Your email client then checks for the key that
calculation generates. Only the people you issue credits to can
send you email. For this reason its no good for email where just
anybody can send you something. For that you need (1) or you issue
a few credits and post them on your freesite and hope they dont colide.
PGP signature
