[pkg-otr-team] Bug#818313: Bug#818313: off-the-record (OTR) plugin actually logs conversations

[micah]

Antoine Beaupré <anarcat at debian.org> writes:

> On 2016-03-16 11:04:14, micah wrote:
>> Antoine Beaupré <anarcat at debian.org> writes:
>>
>>> It's called "off the record" - why the heck would you want to log
>>> that?
>>
>> the 'off the record' property of OTR only has to do with the protocol
>> itself, it doesn't promise anything beyond that. Someone can copy and
>> paste text from the terminal, take a photo or have it read out loud
>> through speakers that are blasting through the grand canyon. OTR's "off
>> the record" only promises these properties:
>>
>> . Encryption - No one else can read your instant messages.
>>
>> . Authentication - You are assured the correspondent is who you think it
>> is.
>>
>> . Deniability - The messages you send do not have digital signatures
>> that are checkable by a third party. Anyone can forge messages after a
>> conversation to make them look like they came from you. However, during
>> a conversation, your correspondent is assured the messages he sees are
>> authentic and unmodified.
>>
>> . Perfect forward secrecy - If you lose control of your private keys, no
>> previous conversation is compromised.
>>
>> You might be thinking that logging by an external program compromises
>> the 'encryption' aspect of OTR?
>
> Yes. In fact, I think it compromises the "encryption", "PFS" and
> "deniability" aspects of the protocol, to be more specific.

It doesn't cryptographically.

You cannot take an OTR conversation that has been logged through an
external means and prove cryptographically that this conversation
actually happened.