Common use of Static Attack Clause in Contracts

Static Attack. ‌ Πselect may involve multiple iterations, where parties either agree on a value and terminate, or restart the protocol. In the proof of the Πselect protocol, an event E is defined, which is claimed to occur with a constant probability. It is argued that when E happens in an iteration, all parties terminate. However, we demonstrate that this claim is not valid, resulting in uncertainty regarding the expected-constant round complexity guarantee of the Πselect protocol. Assuming the preconditions for the Πselect protocol hold (i.e., for every non-faulty parties pi and pj, |= Predj(Vi) and Vi ≠ ∅), we will demonstrate that the argument regarding the round complexity is not valid. Let the static adversary A corrupt p1 before the protocol begins. According to Claim 8, A can make parties terminate Πspread in Epoch 1 of Πselect with the following outputs where Relay1,2 = Relay4,2 = {p1, p2, p3} (no corruption is required): p1 : ⟨(v1, Relay1,1), (v2, Relay1,2), (v3, Relay1,3), (v4, Relay1,4)⟩ p2 : ⟨(v1, Relay2,1), (v2, Relay2,2), (v3, Relay2,3), (v4, Relay2,4)⟩ p3 : ⟨(v1, Relay3,1), (v3, Relay3,3), (v4, Relay3,4)⟩ p4 : ⟨(v2, Relay4,2), (v3, Relay4,3), (v4, Relay4,4)⟩

Static Attack. ‌ Πselect may involve multiple iterations, where parties either agree on a value and terminate, or restart the protocol. In the proof of the Πselect protocol, an event E is defined, which is claimed to occur with a constant probability. It is argued that when E happens in an iteration, all parties terminate. However, we demonstrate that this claim is not valid, resulting in uncertainty regarding the expected-constant round complexity guarantee of the Πselect protocol. Assuming the preconditions for the Πselect protocol hold (i.e., for every non-faulty parties pi and pj, |= Predj(Vi) and Vi ≠ ∅), we will demonstrate that the argument regarding the round complexity is not valid. Let the static adversary A corrupt p1 before the protocol begins. According to Claim 87, A can make parties terminate Πspread in Epoch 1 of Πselect with the following outputs where Relay1,2 = Relay4,2 = {p1, p2, p3} (no corruption is required): p1 : ⟨(v1, Relay1,1), (v2, Relay1,2), (v3, Relay1,3), (v4, Relay1,4)⟩ p2 : ⟨(v1, Relay2,1), (v2, Relay2,2), (v3, Relay2,3), (v4, Relay2,4)⟩ p3 : ⟨(v1, Relay3,1), (v3, Relay3,3), (v4, Relay3,4)⟩ p4 : ⟨(v2, Relay4,2), (v3, Relay4,3), (v4, Relay4,4)⟩