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

2004-01-02 Thread Alan Brown
On Tue, 30 Dec 2003, Bill Stewart wrote: 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

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

2003-12-31 Thread R. A. Hettinga
At 7:46 PM + 12/30/03, Richard Clayton wrote: where does our esteemed moderator get _his_ stamps from ? A whitelist for my friends, etc... Whitelist [EMAIL PROTECTED] Cheers, RAH -- - R. A. Hettinga mailto: [EMAIL PROTECTED] The Internet Bearer Underwriting Corporation

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

2003-12-31 Thread Bill Stewart
At 07:46 PM 12/30/2003 +, Richard Clayton [EMAIL PROTECTED] 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

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

2003-12-31 Thread jal
On Tue, 30 Dec 2003, Bill Stewart wrote: At 07:46 PM 12/30/2003 +, Richard Clayton [EMAIL PROTECTED] 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

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

2003-12-31 Thread Ben Laurie
Richard Clayton wrote: and in these schemes, where does our esteemed moderator get _his_ stamps from ? remember that not all bulk email is spam by any means... or do we end up with whitelists all over the place and the focus of attacks moves to the ingress to the mailing lists :( He uses the

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

2003-12-30 Thread Eric S. Johansson
Scott Nelson wrote: d*b --- s where: d = stamp delay in seconds s = spam size in bytes b = bandwidth in bytes per second I don't understand this equation at all. It's the rate limiting factor that counts, not a combination of stamp speed + bandwidth. well, stamp speed is method of

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

2003-12-30 Thread Alan Brown
On Tue, 30 Dec 2003, Eric S. Johansson wrote: But using your spam size, , the slowdown factor becomes roughly 73 times. So they would need 73 machines running full tilt all the time to regain their old throughput. Believe me, the professionals have enough 0wned machines that this is

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

2003-12-30 Thread Jerrold Leichter
(The use of memory speed leads to an interesting notion: Functions that are designed to be differentially expensive on different kinds of fielded hardware. On a theoretical basis, of course, all hardware is interchangeable; but in practice, something differentially expensive to calculate on an

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

2003-12-30 Thread Richard Clayton
On Tue, 30 Dec 2003, Eric S. Johansson wrote: But using your spam size, , the slowdown factor becomes roughly 73 times. So they would need 73 machines running full tilt all the time to regain their old throughput. Believe me, the professionals have enough 0wned machines that this is

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-29 Thread R. A. Hettinga
At 11:49 AM -0800 12/28/03, Jim Gillogly wrote: wouldn't it be preferable to prove that you've contributed the same amount of power to a useful compute-bound project, such as NFSNET.org or GIMPS or [EMAIL PROTECTED] or [EMAIL PROTECTED] Simple economics. If you're going to go so far as using some

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-29 Thread Bill Stewart
At 09:37 PM 12/26/2003 -0500, Adam Back wrote: The 2nd memory [3] bound paper (by Dwork, Goldber and Naor) finds a flaw in in the first memory-bound function paper (by Adabi, Burrows, Manasse, and Wobber) which admits a time-space trade-off, proposes an improved memory-bound function and also in

Microsoft publicly announces Penny Black PoW postage project

2003-12-28 Thread Steve Schear
http://news.bbc.co.uk/2/hi/technology/3324883.stm Adam Back is part of this team, I think. Similar approach to Camram/hahscash. Memory-based approaches have been discussed. Why hasn't Camram explored them? steve BTW, Penny Black stamp was only used briefly. It was the Penny Red which

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-28 Thread David Honig
At 09:13 AM 12/26/03 -0800, Steve Schear wrote: http://news.bbc.co.uk/2/hi/technology/3324883.stm Mr Wobber and his group calculated that if there are 80,000 seconds in a day, a computational price of a 10-second levy would mean spammers would only be able to send about 8,000 messages a day, at

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-28 Thread Adam Back
I did work at Microsoft for about a year after leaving ZKS, but I quit a month or so ago (working for another startup again). But for accuracy while I was at Microsoft I was not part of the microsoft research/academic team that worked on penny black, though I did exchange a few emails related to

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-28 Thread Ben Laurie
Steve Schear wrote: http://news.bbc.co.uk/2/hi/technology/3324883.stm Adam Back is part of this team, I think. Similar approach to Camram/hahscash. Memory-based approaches have been discussed. Why hasn't Camram explored them? They were only invented recently, and indeed, I've been planning

Re: Microsoft publicly announces Penny Black PoW postage project

2003-12-28 Thread Adam Back
Oh yes forgot one comment: One down-side of memory bound is that it is memory bound. That is to say it will be allocated some amount of memory, and this would be chosen to be enough memory to that a high end machine should not have that much cache so think multiple MB, maybe 8MB, 16MB or