Unconditional Security Clause Samples

Unconditional Security. ≤ We demonstrate the achievability with respect to unconditional security by modifying the ▇▇▇▇▇▇▇▇▇- ▇▇▇▇▇▇▇ precomputation protocol to tolerate t < n. However, more efficient solutions can be achieved by modifying the precomputation protocol in [BPW91] to tolerate t < n/2. This is possible since t + 2t+ < n and t t+. However, the ▇▇▇▇▇▇▇▇▇-▇▇▇▇▇▇▇ protocol is more generic in that it allows for any later broadcast protocol using authentication. p1 ▇▇▇▇▇▇▇▇ ▇ ▇▇▇▇▇▇▇▇+ (▇, ▇▇, ▇, ▇+) 1. Execute precomputation the ▇▇▇▇▇▇▇▇▇-▇▇▇▇▇▇▇ protocol for b + 1 future broadcasts wherein each invocation of broadcast is replaced by an invocation of ECBC+ Protocol 2 with the same sender: pk ExtConsBC+ (P, ·, t, t+). Of these instances, one is computed with respect to the intended sender s ∈ {1,... , n} of the future broadcast. Of the other n instances, one is computed with respect to each player pj ∈ P . 2. G := .A gk where the gk are all grades received during an invocation of ECBC+ during Step 1. i k=1 i i Synchronize: Wait and start executing the next step at round | n2 (9t+10) ∫ + 1. 3. SendToAll(Gi); Receive(G1,... , Gn); i i ∈ For every player pj P as a sender, an instance of Dolev-Strong broadcast is invoked (using pseudo-signatures) where pj inputs Gj. Store all received values as Γ1,... , Γn.