Proposal
The round proposer assembles valid transactions and broadcasts a candidate block.
01 / MODEL
Fault tolerance and quorum
N ≥ 3f + 1
f_max = floor((N - 1) / 3)
Q(N) = ceil(2N / 3)
Launch configuration: N = 4, f = 1, Q = 3
f_max = floor((N - 1) / 3)
Q(N) = ceil(2N / 3)
Launch configuration: N = 4, f = 1, Q = 3
With four validators, any finalized block requires three commits. The standard model tolerates at most one Byzantine validator; loss of two participating validators prevents quorum and stalls finalization.
02 / FINALITY
From proposal to final block
Prepare
Validators independently verify the proposal and broadcast agreement on the block digest.
Commit
A supermajority signs commit messages for the same height, round, and block hash.
Finalization
The commit certificate is embedded and the deterministic EVM state transition becomes canonical.
Final(B,h) ⇔ ValidHeader(B)
∧ Execute(σparent, B.tx).stateRoot = B.stateRoot
∧ |CommitSignatures(B,h)| ≥ Q(N)
∧ Signers(B) ⊆ ValidatorSet(h)
∧ Execute(σparent, B.tx).stateRoot = B.stateRoot
∧ |CommitSignatures(B,h)| ≥ Q(N)
∧ Signers(B) ⊆ ValidatorSet(h)
03 / SAFETY
Why quorums intersect
For quorums A and B where |A|, |B| ≥ Q:
|A ∩ B| ≥ 2Q - N
For N = 4 and Q = 3: |A ∩ B| ≥ 2
|A ∩ B| ≥ 2Q - N
For N = 4 and Q = 3: |A ∩ B| ≥ 2
Because two valid quorums must share at least two validators, their intersection contains an honest validator when f ≤ 1. This supports safety because an honest validator does not commit conflicting blocks for the same consensus context.
04 / EXECUTION
EVM state transition
σ[a] = (nonce, balance, storageRoot, codeHash)
σᵢ₊₁ = Υ(σᵢ, Tᵢ)
σblock = Υ(...Υ(σparent,T₀)...,Tₙ₋₁)
σᵢ₊₁ = Υ(σᵢ, Tᵢ)
σblock = Υ(...Υ(σparent,T₀)...,Tₙ₋₁)