[Cryptography] Dark Mail Alliance specs?

[James A. Donald]

On 2013-11-23 22:30, Ralf Senderek wrote:
> Yes, but it's about time we do something about that. Do we *exactly know
> why* it is such a failure?

Key management.

Need no-click key management.

Assume that secure email/IM addresses look like user#example.com

(Since we are breaking compatibility, we need to distinguish our addresses)

The user#example.com logs on to the mail transport agent at example.com 
using a zero knowledge password protocol.

This generates a transient shared secret between the client and the mail 
transport agent, which changes every logon, and also generates a durable 
client secret, which depends on a strong per client secret maintained by 
the mail transport agent and the user password.

If the user password is weak, whoever controls example.com can find it 
by dictionary attack, and thus find the durable client secret, but no 
one else can, except they first attack the mail transport agent on 
example.com.

If the end user is exceptionally paranoid, he uses a strong password or 
makes sure he controls example.com

The durable client secret gives rise to a durable client public key, 
which is published by example.com.

The corresponding client secret key is recreated every logon, and, all 
being well, is known only to the client.