[12176] in cryptography@c2.net mail archive
RE: Micropayments, redux
daemon@ATHENA.MIT.EDU (Zully Ramzan)
Mon Dec 16 20:31:52 2002
Date: Mon, 16 Dec 2002 17:29:31 -0800
From: "Zully Ramzan" <zramzan@ipdynamics.com>
To: <cryptography@wasabisystems.com>
There are a number of ways to deal with some of the objections that have
come up in this thread; e.g. the unlucky user scenario.=20
Refer to the paper "Micropayments Revisited" written by Silvio Micali
and Ron Rivest: =20
http://theory.lcs.mit.edu/~rivest/publications.html =20
[The powerpoint slides are also quite useful.]
The schemes in this paper combine Payword (Rivest and Shamir) with the
Lottery Ticket proposal (Rivest). They also introduce a number of other
neat ideas. As of the last time I talked to Ron and Silvio about it,
the Peppercoin scheme is based on these techniques. =20
Regards,
Zully =20
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Zulfikar Ramzan
IP Dynamics, Inc. http://www.ipdynamics.com
Secure, Scalable Virtual Community Networks
=20
> -----Original Message-----
> From: David Wagner [mailto:daw@mozart.cs.berkeley.edu]
> Sent: Monday, December 16, 2002 4:47 PM
> To: cryptography@wasabisystems.com
> Subject: Re: Micropayments, redux
>=20
> Matt Crawford wrote:
> >> No, it doesn't. It doesn't take unlimited time for lottery-based
> >> payment schemes to average out; finite time suffices to get the
> >> schemes to average out to within any desired error ratio.
> >
> >Strictly speaking, the average will come within your error tolerance
> >of the expected value *with probability near 1*.
>=20
> Yes, but the probability of it being significantly worse than I
claimed
> (i.e., by more than a factor t) is exponentially small (in t). One
can
> easily calculate concretely exactly what the risk curve looks like.
> I'll spare everyone the details and just say that I see no reason why
> this should be a showstopper in practice.
>=20
> ---------------------------------------------------------------------
> The Cryptography Mailing List
> Unsubscribe by sending "unsubscribe cryptography" to
majordomo@wasabisystems.com
---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo@wasabisystems.com
