random comments, random questions and thread titles made for Google

[chalsall]

Originally Posted by jasong

Whaddaya think?

What is the sound of one hand clapping?

[Nick]

Originally Posted by jasong

Whaddaya think?

There has been quite a bit of research on such ideas. It gets presented at the annual Workshop on Information Security (WEIS):
http://econinfosec.org/

I believe the Dutch postal service offers something similar to your second part, but I don't know how many people have taken it up.

So, yes, interesting ideas!

[LaurV]

Interesting idea, however not new. There are already mail servers which refuses all emails not hash-signed. To send a mail to an address on that email server you have to provide a string that hashes to a value lower than a limit (for example, exactly like bitcoin, see SHA-256), otherwise the mail is scrapped (not sent to the destination address, just ignored). The server provides you a nudge, and you have to add your string to it and hash it until a hash lower than the limit of the server is reached. This can take like one second or two of your computing power. This does not affect the normal guy who sends a honest email, i mean, how many emails you send in a day? But for a spammer, which sends lots of emails, he will need a big computing farm to compute hashes for all of them. So, you can spam as much as you want, but you will have to pay high electricity bills or amazon's fees to do so.