Case 2. In Protocol 1, case 4 was satisfied for Ppred at subround t + j′. This means Ppred received (sid, v, vk, σ) and a valid signature σ, and sent it to all of its neighbors, and in particular Pi′ would receive this message by subround t + j′ + 1. Assume Pi′ has not already output (vk, sid, v′, GradeKeyi′ (vk, sid)) for v′ ∈ {v, ⊥} (otherwise we are already done). In that case, for Pi′ it must hold that Bvk,sid = 0. By Inequality 3.1, GradeKeyi′ (vk, sid) > 0; hence, one of the following must be the case:
Appears in 2 contracts
Sources: Byzantine Agreement, Byzantine Agreement