Re: [ANNOUNCE] contrib/hashcash.el spam fighter

[Stainless Steel Rat <ratinox@peorth.gweep.net>]

* Simon Josefsson <jas@extundo.com>  on Sat, 29 Jun 2002
| To put mail with valid hashcash in a separate, supposedly spam-free,
| mailbox.

But since spammers can generate hashes themselves, your supposedly
spam-free X-Hashcash (not hashcash!) mailbox will not be spam-free.


| I don't understand this argument, the whole point of hashcash is that
| you need to spend CPU to overcome it.  How you aquire that CPU is
| irrelevant.  If all spammers were required to acquire it using sub7,
| people would start to fix the sub7 problem, not stop using hashcash,
| and things would be fine.

Using Sub7 for generating hashes is not a mechanism for sending spam, it is
a Denial of Service attack against the X-Hashcash database, to make it grow
to unweildly size and to fill it with hashes that cause false positives.
All the words matter.

You also still seem not understand what Sub7 is.  I suggest you read up on
in just as I read up on X-Hashcash.


| 30 bits would allow a desktop PC to send 16 mails per day, that's
| probably more that I need.

Yes, well, this is not about -you-.  16 messages in a 24 hour period for me
would basically make it impossible for me to do my job as a Unix admin.

| If you use too few bits (like anything under 23-24), spammers will have
| it to easy to acquire that amount of CPU.  29 bits have been suggested as
| a value to use in practice.

Funny, the defaults I have seen for both X-Hashcash and hashcash are 18-22
bits.

-- 
Rat <ratinox@peorth.gweep.net>    \ Caution: Happy Fun Ball may suddenly
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PGP Key: at a key server near you!  \ 
       That and five bucks will get you a small coffee at Starbucks.