Hashcash is a denial-of-service counter measure tool.

A hashcash stamp constitutes a proof-of-work which takes a parameterizable amount of work to compute for the sender. The recipient can verify received hashcash stamps efficiently.

More info on hashcash:

http://www.hashcash.org/

http://en.wikipedia.org/wiki/Hashcash

http://www.ibm.com/developerworks/linux/library/l-hashcash.html?ca=dgr-lnxw01HashCash

This library provide basic utilities for hashcash creation and validation.

Creating stamps:

mint ( resource -- stamp )

mint* ( tuple -- stamp )

Validation:

check-stamp ( stamp -- ? )

Hashcash tuple and constructor:

hashcash

<hashcash> ( -- tuple )

Utilities:

salt ( length -- salted )