[messaging] Autocrypt 1.0

holger holger at merlinux.eu
Sat Dec 23 00:48:19 PST 2017

On Sat, Dec 23, 2017 at 08:28 +0000, Trevor Perrin wrote:
> On Sat, Dec 23, 2017 at 12:23 AM, Vincent Breitmoser
> <look at my.amazin.horse> wrote:
> >> The recipient of this message will accept and use the incorrect
> >> gossiped keys for group replies, thus sending unreadable messages.
> >
> > I don't think that's right? Keys received directly take precedence over
> > gossip keys, so everyone who participates in the group and has sent at
> > least a single message, will no longer have his key overridden within
> > that group.
> Sure, but anyone in the group who *hasn't* sent a recent message to
> all other group members is at risk of having their key overridden by
> an outsider.

If an outsider gets into people's inboxes with maliciously gossiped keys:

- to do any more than annoy people, the outsider
  also needs to be able to intercept messages to make
  use of injecting the keys

- any MUA that keeps track of when and from whom it 
  received keys could identify the outsider's interference
  (maybe with an additional out-of-band verification step
  with one of the "overriden" affected key holders)

IOW, how do you imagine this attack to practically
happen and have interesting (for the outsider) effects? 


More information about the Messaging mailing list