Services/Sync/P2P Key Exchange And Rotation: Difference between revisions

Version 2 of the eXfio Peer protocol improves the protection against a man in the middle (MITM) attack, at the expense of a more complex protocol, requiring two round-trips. Importantly the starting assumption is that an adversary has full access to the storage '''and''' knows the password, i.e. a hostile systems administrator. Fortunately an elegant means to mitigate against this threat is to use a [https://www.silentcircle.com/products-and-solutions/technology/scimp/ SCIMP] style hash commitment, which results in the adversary having a single opportunity to guess the authcode with a probability of 1.05 x 10^-6.

By first requiring each party to make a hash commitment an adversary is required to select a public key without knowing the other party’s key. Thus making it very difficult to launch a MITM attack without detection. See [[#Registration Protocol v2]]