Well I thought I'd have a go seeing how easy it would be verify a hashcash token in sh script (using sha1sum/sha1 for the SHA1 function). But then I got a bit carried away and now it can fully check a hashcash stamp with same options and syntax as the C command line tool. It can't mint tokens, but actually I think that would also be pretty easy, though perhaps slightly slower than C code. http://www.hashcash.org/libs/ -> sh script I'm not an experienced sh coder, so if anyone has constructive criticisms, or suggested changes, etc send them this way. Adam