Begin forwarded message:

From: Eric S Johansson <esj@esjworks.com> Date: November 2, 2008 3:13:57 PM EST To: "R.A. Hettinga" <rah@shipwright.com> Subject: Re: [gsc] Fwd: Bitcoin P2P e-cash paper

R.A. Hettinga wrote:

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In re: <http://www.bitcoin.org/bitcoin.pdf>

On Nov 2, 2008, at 12:27 PM, R.A. Hettinga wrote:

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On Nov 2, 2008, at 9:52 AM, Patrick Chkoreff wrote:

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That is a great paper.

Shit. Now I have to read the damn thing.

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:-)

Kewl. Nice to see that someone's blown the cobwebs off the stuff that's out there, and done something interesting.

So, one of the things I like is that it's got a distributed mint, kinda like Juels and Jakobsson's Breadpudding scheme for Shamir/Rivest's Micromint.

Not to mention a variant of Adam Back's Hashcash proof of work stuff. I've never been convinced by the Bayes-filter guys' incessant attacks on proof of work schemes like Eric Johansson's Camram, myself, though I've always been more interested in underwriting other things of value besides mere machine horsepower. :-). Looks like this is long-awaited step in the right direction.

just a quick update on the project formerly known as camram and now known as 2 penny blue (came later then and had a higher value than Penny Black. :-). It's still alive albeit suffering from a bit of neglect. I'm currently restructuring it to make it more robust in the face of ill formed messages and add reputation handling. this latter feature is a major shift in my perception of proof of work puzzles with regards to anti-spam. It came because the realization that solving approval work puzzles is an expression of reputation. as a result, this means with reputation data from traffic analysis (i.e. which addresses are the source of lots of good messages), one can use a smaller proof of work puzzle to guarantee delivery for good sites and only guarantee it won't be thrown away sight unseen for neutral or bad sites.

Might not seem like much but early experiments show promise.

Bob, feel free to forward this to anyone you think should see it. (not that I could stop you :-)

hope all is well.

---eric