Sprint 27 Engineering Log

Program Context

• Phase: Phase 6
• Sprint: Sprint 27
• Status: Completed
• Primary Architecture Layers: Audit & State Plane, Verification Plane

Architectural Intent

Implement ledger verification and export capabilities over Sprint 26 append-only core.

Implementation Detail

Implemented:

• Inclusion proof API over signed Merkle roots with deterministic audit path construction.
• Deterministic rebuild mode from immutable leaf records for independent root recomputation.
• Ledger snapshot export in canonical JSON form for verifier-node distribution.
• Read-only verifier node runtime loading snapshots without write access.
• Root mismatch tamper detection validation path for mutated snapshot/DB evidence.

Security and Control Posture

• Inclusion proof structure is immutable and root-signature bound.
• Verifier node independently recomputes roots and validates signatures.
• Tampered evidence chains are detected by deterministic root mismatch.

QA and Validation Evidence

• Unit tests validate inclusion proof generation, snapshot export, read-only verifier behavior, and tamper detection.
• Sprint QA test verifies roadmap completion lines and expected Sprint 27 verifier/export contracts.

Risk Register

• Risk: verifier node currently trusts snapshot file transport channel.
• Mitigation: distribute snapshots over signed transport and pin source identity in Phase 7.

Forward Linkage

Sprint 28 binds C2 adapter execution flow into this verified ledger chain.