Vollcrypt Shield Embedded

vollcrypt-shield-embedded is an independent, zero-allocation #![no_std] integrity-state library for long-lived embedded devices. It does not depend on Wave, an operating system, a network stack, or another Vollcrypt package.

The current foundation provides:

• fixed-capacity, deterministic SHA-256 Merkle measurements;
• a monotonic, tamper-evident audit-chain head;
• signed-checkpoint bytes with versioned SHA-256 and ML-DSA-65 identifiers;
• a hardware/secure-element signer trait that keeps private keys outside the library;
• scope-local containment that blocks baseline replacement until a signed, bounded break-glass command is verified; and
• compile checks for Cortex-M33, Cortex-M4, and RV32 targets.

The application supplies component identifiers, digests, monotonic counters, persistent storage, notifications, and an ML-DSA-65 implementation through the documented traits. A software counter or key stored in the same writable trust domain as monitored firmware is a weak trust root. Cortex-M33 deployments should place counters and signing behind TrustZone-M or a secure element.

This crate does not implement a bootloader, flash driver, network isolation, device shutdown, or remote fleet control. Commercial centralized fleet management is described publicly but implemented in a separate private repository.

Licensed under GPL-3.0-only OR LicenseRef-Commercial.