The Matrix Scroll protocol underpins code provenance and release integrity, so security reports get priority handling.

Please do not file public GitHub issues for security vulnerabilities.

Instead:

1. Email security@matrixscroll.com with a description of the issue, a proof-of-concept if available, and your preferred disclosure timeline.
2. Or open a private GitHub Security Advisory at https://github.com/SSX360/matrixscroll/security/advisories/new.

We aim to acknowledge new reports within 3 business days and to have a remediation or mitigation plan within 30 days for confirmed issues.

In scope:

• Cryptographic correctness of the signing and verification paths.
• Canonical encoding determinism (any input that produces different signing bytes across platforms, locales, or Python versions).
• Private key disclosure or persistence beyond the documented store.
• Provider isolation (any path that lets a caller exfiltrate a private seed).
• CLI behavior that produces incorrect verify results.

Out of scope:

• Vulnerabilities in upstream dependencies (cryptography, CPython) — please report those to the relevant project. We will track and update pins.
• Issues that require an attacker to already have local filesystem access at the same privilege level as the user running the SDK (these are documented trust boundaries; the secure element exists to address them).

Pre-1.0 there is no extended support window. Pin to a known-good version in production until 1.0.

We follow a coordinated-disclosure model. Once a fix is available we publish a GitHub Security Advisory with a CVE (where applicable) and credit the reporter unless anonymity is requested.

• Signing: Ed25519 (RFC 8032) via cryptography's Ed25519PrivateKey.
• Hashing for device id derivation: SHA-256 (truncated to 8 hex chars for the human-readable id; the full key is the actual identity).
• Canonical encoding: JSON with sorted keys, ASCII escaping, allow_nan=False, and the signature block excluded from the signing input. See SPEC.md.

Changes to any of the above are breaking and bump the protocol schema version.