Resilience, Backup, and Deterministic Recovery

The plant is designed to recover to a known-good state from signed artifacts and verified backups, so an incident ends in restoration rather than uncertainty.

Recovery is a security control

Availability and integrity after an incident depend on being able to rebuild the control environment to a state you can trust. Kronos designs recovery as a first-class control: golden, signed firmware and model images; verified, integrity-checked backups of configuration and accountancy; and a deterministic procedure to re-provision nodes so that a recovered plant is provably known-good, not merely rebooted.

What is backed up and how

• Golden images: signed firmware, bitstreams, and approved models with provenance, stored offline.
• Configuration and policy: segmentation rules, identities' issuance policy, safety limits - versioned and hashed.
• Records: the tamper-evident audit log and material accountancy, mirrored offsite via the diode.
• Immutable, offline copies so ransomware or an insider cannot encrypt or delete the only copy.

Deterministic re-provisioning

# Rebuild a node to known-good and require attestation before rejoin
def recover_node(node):
    flash(node, golden_image(node.role))        # signed, verified image
    if not attest(node):                         # must prove firmware match
        quarantine(node); return FAIL
    issue_cert(node)                             # short-lived identity
    rejoin_segment(node)                         # default-deny still applies
    return OK

Backups must be trustworthy too

A backup an attacker can tamper with is a liability. Backups are integrity-checked on restore, and restoring never bypasses verification: a restored image still passes signature and attestation checks before it runs. The twin can validate a recovered configuration by replaying known decisions before the plant returns to service.

Design status: golden-image management, offline immutable backups, and deterministic re-provisioning run in the twin/staging environment and are drilled during red-team exercises. Live recovery drills on plant hardware are FOAK-era; no operating reactor has yet been recovered under this procedure.