[liberationtech] Not another Haystack right?

[Jacob Appelbaum]

On 11/29/2011 12:11 PM, Michael Rogers wrote:
> Hi Jake,
> 
> Thanks for the feedback.

Sure, it's nice to see you on this list. I hope someone smart decides to
fund you and that you hire some C programmers. This java bikeshed is
really breaking my heart. :)

> 
> On 29/11/11 19:32, Jacob Appelbaum wrote:
>> Indeed, while I like the idea for a sneakernet, I think `gpg -R` does
>> the job fine most times, no?
> 
> As far as I can tell, GPG uses long-term keys for encryption and
> authentication, so there's no forward secrecy or repudiation.
> 

It can use symmetric keys. The '-R' option is interesting:

    Encrypt for user ID name, but hide the key  ID  of  this  user's
    key.  This  option helps to hide the receiver of the message and
    is a limited countermeasure against traffic  analysis.  If  this
    option  or --recipient is not specified, GnuPG asks for the user
    ID unless --default-recipient is given.

> The Briar protocol is closer to OTR in that respect: once a connection
> has been torn down and the endpoints have destroyed their ephemeral
> keys, there's no way to decrypt the connection or prove that the
> endpoints authenticated it.
> 

OTR uses long term identity keys to establish those ephemeral keys. You
can build OTR from the OpenPGP building blocks.

> (Messages sent over the connection may or may not be repudiable by their
> authors, depending on whether they're anonymous or pseudonymous, but
> that's a separate issue.)

Sure - that's a feature as I understand it.

All the best,
Jake