> On Jun 28, 2016, at 10:36 PM, Peter Todd <p...@petertodd.org> wrote: > >> On Tue, Jun 28, 2016 at 10:29:54PM +0200, Eric Voskuil wrote: >> >> >>>> On Jun 28, 2016, at 10:14 PM, Peter Todd <p...@petertodd.org> wrote: >>>> >>>> On Tue, Jun 28, 2016 at 08:35:26PM +0200, Eric Voskuil wrote: >>>> Hi Peter, >>>> >>>> What in this BIP makes a MITM attack easier (or easy) to detect, or >>>> increases the probability of one being detected? >>> >>> BIP151 gives users the tools to detect a MITM attack. >>> >>> It's kinda like PGP in that way: lots of PGP users don't properly check >>> keys, >> >> PGP requires a secure side channel for transmission of public keys. How does >> one "check" a key of an anonymous peer? I know you well enough to know you >> wouldn't trust a PGP key received over an insecure channel. >> >> All you can prove is that you are talking to a peer and that communications >> in the session remain with that peer. The peer can be the attacker. As Jonas >> has acknowledged, authentication is required to actually guard against MITM >> attacks. > > Easy: anonymous peers aren't always actually anonymous. > > A MITM attacker can't easily distinguish communications between two nodes that > randomly picked their peers, and nodes that are connected because their > operators manually used -addnode to peer; in the latter case the operators can > check whether or not they're being attacked with an out-of-band key check.
An "out of band key check" is not part of BIP151. It requires a secure channel and is authentication. So BIP151 doesn't provide the tools to detect an attack, that requires authentication. A general requirement for authentication is the issue I have raised. e _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
