Shield Offline Packages

Shield offline packages are deterministic-CBOR transfer envelopes for physical or otherwise disconnected movement of signed evidence. They do not encrypt the payload. Use encrypted removable media when confidentiality is required.

Signed fields

Each ML-DSA-65 signature covers the exact payload and canonical manifest. The manifest includes:

• protocol version, random package ID, and payload type;
• sender key ID and channel ID;
• creation and expiry times, with a maximum 30-day lifetime;
• sequence and previous package hash;
• SHA-256 payload hash and payload length.

Payloads are limited to 16 MiB. Package readers reject symlinks, oversized files, trailing CBOR data, expired packages, wrong trusted keys, and inner records whose signer does not match the outer sender.

First package

vollcrypt-shield fleet-summary --config shield.toml --scope default --epoch 1 --output summary-1.cbor
vollcrypt-shield offline-pack --config shield.toml --kind fleet-summary --channel production-summaries --input summary-1.cbor --sequence 1 --output summary-1.vcsp

Sequence 1 requires an all-zero previous hash, which the CLI supplies when --previous-hash is absent.

Continued chain

Use the first command’s summaryHash as the next fleet summary’s --previous-hash. Use the first offline-pack command’s packageHash as the next package’s --previous-hash:

vollcrypt-shield fleet-summary --config shield.toml --scope default --epoch 2 --previous-hash <SUMMARY_HASH_1> --output summary-2.cbor
vollcrypt-shield offline-pack --config shield.toml --kind fleet-summary --channel production-summaries --input summary-2.cbor --sequence 2 --previous-hash <PACKAGE_HASH_1> --output summary-2.vcsp

Receiving

For a one-off extraction, the receiver supplies the expected sender key and chain position:

vollcrypt-shield offline-unpack --package summary-2.vcsp --expected-public-key node-a.public --expected-sequence 2 --previous-hash <PACKAGE_HASH_1> --output summary-2.cbor

For durable fleet ingestion, the control plane stores the channel cursor in its signed state:

# Licensed fleet deployments import the package through their private service interface.

Viewer verifies a selected package and trusted public key without writing the inner payload. It verifies package authenticity, expiry, payload digest, and the type-specific inner signature. Viewer does not persist a replay ledger, so sequence continuity after package 1 must be checked through the CLI, control plane, or another externally pinned cursor.