Partial synchrony and network layer


#1

Hi,

Partial synchrony assumes that messages between honest participants are not lost. This assumption, if I understand correctly, is needed for liveness. How is this guaranteed at network layer? (Given the big number of participants, having direct links between all participants does not seem as a feasible solution.)

Thank you!


#2

Found this in the paper about Ouroboros Genesis:

Communication. The parties interact which each other by means of a network of eventual delivery unicast channels [3]—informally, every party Up has an open incoming-connections interface where he might receive messages on from arbitrary other parties. This captures the natural joining procedure of real-worlds blockchains where new parties find a point of contact and use it to communicate with other parties by means of a gossiping (flooding) protocol. As argued in [3] assuming the honest parties are strongly connected, this netowrk can be used to build the (UC version of the) standard multicast network with eventual delivery assumed in [16, 26, 21].

Could someone confirm if this is a possible answer to my question?

Thank you!


#3

Hi! The “Ouroboros Praos” paper is solely devoted to describing the protocol under the partial synchronicity, so please check it out: https://eprint.iacr.org/2017/573

Basically the safety guarantees within it work as a gradient, where it gracefully degrades from being as secure as absolutely synchronous setting down to requiring up to 2/3-ds of the honest participation in the worst case, as synchronicity worsens.


#4

Hi, thanks, but i was asking about liveness and about the network layer…


#5

Ah! Sorry 'bout that, missed the specifics :slight_smile:

Yes, this description looks like the best to date on this particular matter :ok_hand: