[cap-talk] email

Brian Warner warner at lothar.com
Fri Jan 16 12:12:57 EST 2009

On Wed, 14 Jan 2009 18:27:25 -0500
"Anupam Simlot" <gurudevdas at gmail.com> wrote:

> E-mail is currently the most anarchic and abused part of
> the wild wild west, err sorry, the internet. I'm sure
> you're all aware of what's wrong with it so I won't
> delve into that here. What I would like to propose is an
> alternative, yet backwards compatible, system based on
> the concept of ocaps.

You might be interested in a project I worked on a couple of years ago.. I
implemented a prototype of a scheme with a lot of the same properties you're
talking about.


In Petmail, the capability of interest is the right to put a message in front
of the recipient's eyeballs. Agents talk to each other without constraint,
but unless the message is signed by a private key which has been designated
as having the right to send messages, the receiving agent will simply discard
it. Each "identity" has a keypair, all messages are signed+encrypted, and a
layer of "permission records" keeps track of what those private keys are
allowed to do. The agents exchange permission records, and a lot of the
design is centered on making it easy for users to manage those permissions
(including revocation, introduction, and automatically establishing
bidirectional links). A pluggable third-party CAPTCHA mechanism can be used
to rate-limit new senders (to reduce the spam vector).

Unfortunately I haven't had the time to work on it much since then.. maybe
it's time to revisit it. The code's all online, though.


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