The future of security

Steven M. Bellovin smb at
Wed May 26 11:59:16 EDT 2004

In message <010501c44325$a6d62700$4900a8c0 at>, "Anton Stiglic" writes:
>----- Original Message ----- 
>From: "Steven M. Bellovin" <smb at>
>> >
>> >j.  a cryptographic solution for spam and
>> >viruses won't be found.
>> This ties into the same thing:  spam is *unwanted* email, but it's not 
>> *unauthorized*.  Crypto can help with the latter, but only if you can 
>> define who is in the authorized set of senders.  That's not feasible 
>> for most people.
>Something like hashcash / client puzzles / Penny Black define a set
>of authorized email (emails that come with a proof-of-work), and then
>provide a cryptographic solution.   This is not a full-proof solution (as
>described in the paper Proof-of-Work Proves Not to Work), 
>but a good partial solution that is probably best used in combination
>with other techniques such as white-lists, Bayesian spam filters , etc...
>I think cryptography techniques can provide a partial solution to spam.
The spammers are playing with other people's money, cycles, etc.  They 
don't care.

		--Steve Bellovin,

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