[144906] in cryptography@c2.net mail archive
Re: [Barker, Elaine B.] NIST Publication Announcements
daemon@ATHENA.MIT.EDU (Steven Bellovin)
Wed Sep 30 11:46:00 2009
Cc: Stephan Neuhaus <neuhaus@st.cs.uni-sb.de>, cryptography@metzdowd.com
From: Steven Bellovin <smb@cs.columbia.edu>
To: "Perry E. Metzger" <perry@piermont.com>
In-Reply-To: <87tyylq0uy.fsf@snark.cb.piermont.com>
Date: Tue, 29 Sep 2009 23:07:57 -0400
On Sep 29, 2009, at 10:31 AM, Perry E. Metzger wrote:
>
> Stephan Neuhaus <neuhaus@st.cs.uni-sb.de> writes:
>> For business reasons,
>> Alice can't force Bob to use a particular TTA, and it's also
>> impossible to stipulate a particular TTA as part of the job
>> description (the reason is that Alice and the Bobs----great band name
>> BTW---won't agree to trust any particular TTA and also don't want to
>> operate their own).
>
> You don't need such a complicated description -- you're just asking
> "can
> I do secure timestamping without requiring significant trust in the
> timestamping authority."
>
> The Haber & Stornetta scheme provides a timestamping service that
> doesn't require terribly much trust, since hard to forge widely
> witnessed events delimit particular sets of timestamps. The only issue
> is getting sufficient granularity.
I don't know if their scheme was patented in Germany. It was in the
U.S., though I think that at least some of the patents expire within
the year.
--Steve Bellovin, http://www.cs.columbia.edu/~smb
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