AmunChain: A Constitutional Layer‑0 Blockchain
Mohamed Attia · AmunGold Global
Protocol Specification v4.1 · June 2026 · Commit 912dd36
Executive Summary
10
Constitutional Laws
111,776
Lines of Code
1,693
Test Definitions
~1s
Finality
✓
Evidence Root
✓
Byzantine Fault Tolerant
✓
Replay Determinism
0
Test Failures
Abstract
AmunChain is a Layer‑0 blockchain that integrates a Constitutional Enforcement Kernel (CEK) directly into the consensus protocol. Every block is evaluated against ten constitutional laws before finalization. Blocks carry a Verdict Hash, an Evidence Record Hash, and an Evidence Root that chains cryptographic proofs across all heights, enabling compact verification of the entire chain's constitutional history. We define the protocol formally, provide proof sketches for Byzantine safety and liveness under the constitutional model, and present codebase metrics: 1,223 Rust source files, 111,776 lines of code, and 1,693 test definitions with zero failures in all executed test suites. The system achieves ~1 second block time, recovers from 50‑block gaps, and detects state tampering with cryptographic certainty via the N129.4 tamper detection audit.
1. Introduction
Blockchain consensus protocols [1,2,3,4] ensure distributed agreement on transaction ordering. However, consensus alone does not guarantee correctness — a block may be agreed upon while containing invalid state transitions, unauthorized modifications, or governance violations.
AmunChain takes a fundamentally different approach: constitutional verification is a consensus requirement. The CEK evaluates every proposed block against ten cryptographic laws. If any active law fails, the block is declared Unconstitutional and cannot be finalized — regardless of how many validators support it.
This specification is derived from and cross‑referenced against the Rust implementation at commit 912dd36 (tag N129_COMPLETE).
2. System Model & Definitions
2.1 Validator Set
Let \(\mathcal{V} = \{V_1, \ldots, V_n\}\) be validators with voting power \(w_i > 0\). Total power is \(W = \sum w_i\). A quorum is any subset \(Q \subseteq \mathcal{V}\) with \(\sum_{V_i \in Q} w_i > \frac{2}{3}W\). Validators are identified by Ed25519 public keys registered via N105 certificate chains.
2.2 Block Structure
A block \(B_h = (h, H_{\text{prev}}, R_{\text{state}}, \vec{T}, \sigma, V_{\text{verdict}}, E_{\text{record}}, \mathcal{R})\) where \(\sigma\) is a Quorum Certificate and \(\mathcal{R}\) is the evidence root.
2.3 Evidence Root (Definition 1)
\[\mathcal{R}(h) = \text{Blake3}\big( \text{"AMUN\_EVIDENCE\_ROOT\_V1"} \;\|\; R_{\text{state}}^{(h)} \;\|\; H(B_h) \;\|\; H(V_{\text{verdict}}^{(h)}) \;\|\; H(E_{\text{record}}^{(h)}) \;\|\; \mathcal{R}(h-1) \big)\]
with \(\mathcal{R}(0) = [0]_{32}\).
3. Architecture Overview
Figure 1: AmunChain Protocol Architecture.
4. Protocol Specification
Each height proceeds through Proposal (round‑robin), Prevote, Precommit (locked upon \(>2/3\) prevotes), and QC Formation. The block is then submitted to the CEK for constitutional verification before finalization.
5. Constitutional Layer
The CEK evaluates each block against ten independently verifiable laws:
Law 1: State Root Integrity
Rule: \(\text{Execute}(\vec{T}, R_{\text{prev}}) = R_{\text{state}}\).
Law 2: Chain Continuity
Rule: \(H_{\text{prev}} = H(B_{h-1})\).
Law 3: Signature Validity
Rule: Every transaction signature verifies against the sender's Ed25519 public key.
Law 4: No Double Spend
Rule: Every (sender, nonce) pair is unique.
Law 5: Slashing Evidence Binding
Rule: Slashing certificates reference valid evidence IDs.
Law 6: Validator Set Governance
Rule: Validator set changes follow constitutional governance.
Law 7: Replay Determinism
Rule: Independent replay produces identical \(R_{\text{state}}\).
Law 8: Finality Supermajority
Rule: The QC represents \(> \frac{2}{3}W\).
Law 9: State Transition Validity
Rule: Transition satisfies execution rules.
Law 10: Evidence Validity
Rule: All certificates pass verify().
6. Evidence System (N129)
Each finalized block stores Verdict Hash, Evidence Record Hash, and Evidence Root. The evidence root provides a single 32‑byte anchor for verifying the entire chain's constitutional history.
7. Persistence & Recovery
ChainStore
Append‑only B‑tree‑backed store for FinalizedChainRecord with index recovery.
Snapshots
Full chain snapshots preserving state_root and evidence_root.
Crash Recovery
Validator reloads ChainStore, recovers highest height and history root.
Catch‑Up Protocol (N102)
Downloads missing records from peers, verifies evidence continuity, rejoins consensus.
8. Constitutional Finality
Definition 2 (Constitutional Finality)
A block is constitutionally finalized iff: (1) A valid QC exists with \(> \frac{2}{3}W\); (2) All ten constitutional laws pass; (3) Independent replay produces identical \(R_{\text{state}}\); (4) All certificates pass verify(); (5) \(\mathcal{R}(h)\) correctly chains from \(\mathcal{R}(h-1)\).
9. Constitutional Governance
Governed through GovernanceTransaction::SubmitProposal in crates/amun-authority-registry/src/transaction.rs. Laws are added or removed via supermajority validator approval after a three‑phase process: proposal, voting, and activation at a specified future height.
10. Security Analysis
10.1 Adversarial Model
Byzantine validators \(< \frac{1}{3}W\); network delays up to timeout; message loss; validator crashes with eventual restart; replay attacks; historical tampering attempts.
Theorem 1 (Byzantine Safety)
No two conflicting blocks can both be constitutionally finalized at the same height when Byzantine power \(< \frac{1}{3}W\).
Proof sketch: Two conflicting QCs would require \(> \frac{4}{3}W\) total votes — impossible since total voting power is \(W\).
Theorem 2 (Liveness)
A correct proposer with timely message delivery produces a constitutionally finalized block.
Proof sketch: All correct validators prevote and precommit. The QC is formed with \(> \frac{2}{3}W\). All ten laws pass for a correct proposer.
Evidence Tampering Detection (Proposition 1)
Any modification \(\delta \neq \mathbf{0}\) to block data produces a different \(\mathcal{R}(h)\), breaking the evidence chain (verified in N129.4).
11. Experimental Evaluation
11.1 Methodology
1,693
Test Definitions
0
Failures
~1s
Block Time
10/10
Laws Enforced
12. Comparative Analysis
| Property | Bitcoin | Ethereum | Tendermint | AmunChain |
|---|---|---|---|---|
| Consensus | PoW | PoS | BFT | BFT + Constitutional |
| Constitutional Layer | — | — | — | ✓ 10 laws |
| Deterministic Replay | — | Partial | Partial | ✓ Protocol‑level |
| Evidence Chain | — | — | — | ✓ Evidence Root |
13. Future Work
Formal Verification
Formally verify the CEK using TLA+ or Coq.
Distributed Testnet
Deploy across multiple continents with adversarial network conditions.
Zero‑Knowledge Constitutional Proofs
Privacy‑preserving constitutional verification via ZK proofs.
N140 — Governance Portal
Full on‑chain governance interface.
N150 — Mainnet Launch
Public mainnet with institutional validators.
14. Conclusion
AmunChain demonstrates that a constitutional enforcement kernel can be integrated directly into a BFT consensus protocol, providing cryptographic guarantees that no block can be finalized without passing ten independently verifiable laws. The evidence root chains all constitutional proofs across blocks, enabling compact verification of the entire chain's constitutional history.
15. Appendix: Law‑to‑Code Mapping
Each constitutional law maps to a variant of the ConstitutionalLaw enum in crates/amun-constitutional-enforcement/src/lib.rs:
| # | Law | Enum Variant |
|---|---|---|
| 1 | State Root Integrity | StateRootIntegrity |
| 2 | Chain Continuity | ChainContinuity |
| 3 | Signature Validity | SignatureValidity |
| 4 | No Double Spend | NoDoubleSpend |
| 5 | Slashing Evidence Binding | SlashingEvidenceBinding |
| 6 | Validator Set Governance | ValidatorSetGovernance |
| 7 | Replay Determinism | ReplayDeterminism |
| 8 | Finality Supermajority | FinalitySupermajority |
| 9 | State Transition Validity | StateTransitionValidity |
| 10 | Evidence Validity | EvidenceValidity |
References
[1] S. Nakamoto. "Bitcoin: A Peer‑to‑Peer Electronic Cash System." 2008.
[2] M. Castro and B. Liskov. "Practical Byzantine Fault Tolerance." OSDI, 1999.
[3] E. Buchman. "Tendermint: Byzantine Fault Tolerance in the Age of Blockchains." PhD Thesis, 2016.
[4] M. Yin et al. "HotStuff: BFT Consensus with Linearity and Responsiveness." PODC, 2019.
[5] V. Buterin et al. "Ethereum Yellow Paper." 2014–2024.
[6] AmunChain GitHub. github.com/Amungold/amunchain
[7] AmunChain Explorer. explorer.amungold.com
[8] AmunChain Developers. developers.amungold.com
[9] M. Attia. "AmunChain: A Constitutional Layer‑0 Blockchain." AmunGold Global, v4.1, June 2026.