NotaryServices
DigitalSignatureDeployment is hampered by an insufficiently powerful notion of trust or key validity.
In Why Rights Management is Wrong (and What to Do Instead), his paper for the 2001 Workshop on Digital Rights Management for the Web, Mark S. Manasse argued that notary services could help with the balance between rightsholders and fans.
Notary services can be used to connect digital signatures to a number of meaningful credentials.
Secure Author Credentials
To claim "I'm the guy who wrote that article" securely, note that only the author can sign an article before it was published.
Retrospective Credentials
now it's too late for me to do this for HTML 2.0 etc., but I expect we can retrospectively validate my claims based on new relationships.
Secure Developer Credentials
likewise "I'm the guy who wrote this code" or "this patch" of course. Which SCM systems have integrated digital signatures?
Secure Software Vendor Credentials
Which SoftwarePackaging systems have integrated signature checking? ZeroInstall does. Does ZeroInstall address licensing issues? Does tim's design note on installation? Software installation is novel w.r.t. caching in that it's an expression of trust: "I trust this software to faithfully execute the instructions I give it." Hmm... orthogonal to or in conflict with GPL "no warrantees"?
Bootstrapping trust via meetings
How about meetings? perhaps generate a large random number and distribute it to the meeting participants (and only the meeting participants) and have them sign it right away -- during roll call, or at least before the end of the meeting. i.e. the meeting participants are defined, securely, as "those who knew this secret before time T".
where are those papers on decentralized secure time services? Ah.. thanks, Rohit! Haber, 1991. I contributed that link to wikipedia on Digital timestamping.
I wonder if this topic is really a community consensus thing, or if I should move it to my research blog.
PGP Digital Timestamping Service
There's an IETF WG: Long-Term Archive and Notary Services (ltans) started around March 2004