Re: [camram-spam] Re: Microsoft publicly announces Penny Black PoW postage project

At 07:46 PM 12/30/2003 +0000, Richard Clayton <richard@xxxxxxxxxxxxxx> wrote:
> [what about mailing lists]
Obviously you'd have to whitelist anybody's list you're joining
if you don't want your spam filters to robo-discard it.

> <moan>
> I never understand why people think spam is a technical problem :( let
> alone a cryptographic one :-(
> </moan>

The reason it's partly a cryptographic problem is forgeries.
Once everybody starts whitelisting, spammers are going to
start forging headers to pretend to come from big mailing lists
and popular machines and authors, so now you'll not only
need to whitelist Dave Farber or Declan McCullough if you read their lists,
or Bob Hettinga if you're Tim (:-), you'll need to verify the
signature so that you can discard the forgeries that
pretend to be from them.

You'll also see spammers increasingly _joining_ large mailing lists,
so that they can get around members-only features.
At least one large mailing list farm on which I've joined a list
used a Turing-test GIF to make automated list joining difficult,
and Yahoo limits the number of Yahoogroups you can join in a day,
but that's the kind of job which you hire groups of Indians
or other English-speaking third-world-wagers to do for you.







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