RE: 'E-postmark' gives stamp of approval

[Amir Herzberg]

Cryptographically, the solution they (AuthentiDate) offer is basic:
timestamping and authentication (non-repudiated origin identification) by a
single trusted authority (USPO). I hope it's well implemented and that it
would succeed; it can definitely provide a substantial advantage over
current e-mail...

I don't think it can help much as solution against spamming, by itself:
people will use timestamped mail only when needed, which means you can't
filter out all non-timestamped mail. Of course it could help as a mechanisms
to filter out new correspondants, if used together with appropriate
mechanism for identifying known recipients, which seems to me the right way
to handle spam.

Two points worth imporving:
1. Their scheme uses a single authority. It would be better to allow use of
multiple authorities for reliability, security, and competition (Ok, maybe
AuthentiDate as a company prefers to have only one service...)
2. They offer only non-repudiation of origin; it's a pity they don't offer
also non-repudiation of submission, this could be really useful
certified-mail feature for B2B. The protocols required are not much more
complex (see e.g. my recent work http://eprint.iacr.org/2002/084/).

Regards,

Amir Herzberg
http://amir.herzberg.name



> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of R.
> A. Hettinga
> Sent: Wednesday, November 27, 2002 5:07 PM
> To: Digital Bearer Settlement List; [EMAIL PROTECTED]
> Subject: 'E-postmark' gives stamp of approval
>
>
> 
>http://seattletimes.nwsource.com/cgi-bin/PrintStory.pl?document_id=3D134580416&zsection_id=3D268448455&slug=3Dcomdex21&date=3D>20021121
>
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