Sprint 35 Engineering Log

Program Context

• Phase: Phase 10
• Sprint: Sprint 35
• Status: Completed
• Primary Architecture Layers: Runner identity, attestation, key lifecycle

Architectural Intent

Extend hardware-assisted isolation with TPM-backed identity contracts, per-execution ephemeral key derivation, and runner-control-plane mutual attestation.

Implementation Detail

Implemented scope:

• Added Sprint 35 attestation contracts (src/pkg/runner/attestation.py)
• Added TPM identity evidence provider (simulation-safe contract)
• Added per-execution ephemeral key derivation using execution context binding
• Added mutual attestation service for runner-control-plane session binding
• Added multi-tenant isolation stress validator for binding-collision checks
• Integrated mutual attestation + ephemeral key metadata into firecracker execution telemetry (src/pkg/runner/universal.py)
• Added unit tests and QA checks for Sprint 35 artifacts

Security and Control Posture

• Zero-trust delegation and execution fingerprint architecture remain intact.
• Firecracker execution path now includes additional identity and session-binding metadata.
• Mutual attestation failures fail closed at execution boundary.

QA and Validation Evidence

Validation evidence:

• pytest tests/unit/test_runner_attestation.py
• pytest tests/unit/test_universal_edge_runner.py
• pytest tests/qa/test_sprint35_mutual_attestation_qa.py

Risk Register

Primary risk is simulation/native attestation parity gap for on-prem TPM environments. Mitigation:

• deterministic contracts in simulation mode
• strict fail-closed mutual attestation checks
• explicit future extension path for real TPM quote verification providers

Forward Linkage

Phase 10 closure continues with operational hardening and native host deployment runbooks.