[hashcash] Re: PR Problem?

> Yes, theoretically a spammer could mint a single stamp, and then
> send out individualized messages, 

yes, thats the prediction that spammers would do that:

> but that would increase the overhead at the sending server,
> essentially accomplishing the same thing as minting stamps
> (e.g. increasing the CPU cost).

I think there is a mistake in this part of your argument around step 4:

>     4. The recipient's filtering pipeline considers the length of the
>        recipient list.

The recipients filter wont know how long the recipient list is and
cant detect reuse across different recipients.

(These issues are the motivation for including the recipients address
in the stamp).

Adam

On Sun, Nov 12, 2006 at 09:01:11PM -0800, Todd A. Jacobs wrote:
> On Sun, Nov 12, 2006 at 06:09:11PM -0500, Eric S. Johansson wrote:
> 
> > BCC is a royal pain in the butt.  I took the brute force bloody
> 
> I can see the problem. But isn't the problem caused by hashing the
> destination address, requiring a hash for each recipient?
> 
> What if--and feel free to say something if I'm missing something
> obvious--hashcash was hashing something less variable such as the
> messageID or the message body? Granted, it would mean that a stamp is
> now per-message rather than per-recipient and therefore lowering it's
> value in preventing long recipient lists, but the value wouldn't fall to
> zero.

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