[messaging] Metadata free instant messaging protocol, with basic spam throttling

[Adam Langley]

On Mon, Sep 29, 2014 at 2:48 PM, Mike Hearn <mike at plan99.net> wrote:
> This message proposes a protocol for a TextSecure-like async mobile
> messaging protocol, in which the central server does not learn who is
> messaging who. Despite that, basic anti-abuse techniques are supported. Our
> tools will be BBS group signatures, Chaumian blind signatures, Tor,
> certificates and a few other misc things which are taken as given (e.g.
> Axolotl).

BBS group signatures are very attractive. However, I'm dropping them
in Pond for reasons of complexity and replacing them with HMAC, thanks
to an idea from Trevor. I think you could do something similar here
and also save a lot of complexity:
https://moderncrypto.org/mail-archive/messaging/2014/000409.html


Cheers

AGL