[Spambayes] Two Stage Plan

Kaitlin Duck Sherwood ducky at webfoot.com
Wed Jan 15 22:31:29 EST 2003

(Sorry I'm late to this particular discussion on using postage...)

I'd like to suggest
+ making the postage stamp computationally VERY expensive for the client, and
+ assume that users look at postage as only one factor in judging spaminess.

For example, hypothetically:
+ For me, anybody on my whitelist gets their messages through without postage.
+ For Frieda, any message without postage gets through if it's got a 
SpamAssassin score of less than 3.
+ For Paul, any message that his Bayesian algorithm rates as <20% 
likely to be spam gets through without postage.
+ For Chantelle, any message without postage gets a 
reverse-Turing-test challenge.

If postage is only one factor, then it can be useful before 
"everybody" adopts it.  If postage is only one factor, then listbots 
can insist on one postage unit for messages that the listbot 
receives, but the listbot can then send out out messages (to the 
teeming hordes on the list) without postage

I want postage to be computationally *very* expensive.  Like five or 
ten minutes on a (currently) high-end desktop.  I want strangers to 
have to spend some time -- not just money -- to be sure that I'll 
read their messages.  Shoot, I don't even care if there is no money 
involved at all, "only" time.

I also want the reverse algorithm -- where I check to see if their 
token is valid -- to be very fast.

So are there any one-way algorithms that would involve my email 
address and some other piece of changing data, like seconds since Jan 
1, 1970?  Or perhaps make and use a Web service that generates and 
posts random time-stamped numbers?  (A web service with random, 
time-stamped numbers could also provide for essentially constant 
difficulty as processors get higher-powered, e.g. the random numbers 
keep getting bigger.)

BTW, anyone who is going to the spam conference, look for me in the 
colored (probably purple) beret!  

More information about the Spambayes mailing list