pcc-verify 0.1.0

Verify your own Apple Intelligence requests against Apple's Private Cloud Compute transparency log

pcc-verify

Check your own Apple Intelligence requests against Apple's Private Cloud Compute transparency log — cryptographically, from your own exported data.

Apple makes a strong commitment for Private Cloud Compute (PCC): every production software release is recorded in a public, append-only, cryptographically tamper-proof transparency log, and your device refuses to send data to unlogged software. Apple also lets you export a record of your own requests (Settings → Privacy & Security → Apple Intelligence Report). But nothing connected the two — "PCC is verifiable" stayed a claim unless you set up Apple's full Virtual Research Environment. This tool connects them: it takes your exported report and checks each PCC request's attestation against the public log.

What this release actually achieves

This is the full-verification shape (of the full / partial / interpretation-only outcomes considered in docs/FEASIBILITY.md): the exported report contains, per PCC node, complete attestation bundles — software measurements plus a Merkle inclusion proof — and Apple's transparency log is publicly queryable. For every request with attestation data, pcc-verify:

1. recomputes the Merkle root from the embedded inclusion proof and checks it against the signed log head your device trusted;
2. recomputes the release digest from the bundle's own OS and cryptex tickets (Apple's documented canonicalization) and checks it equals the digest committed in the log leaf — binding the proof to the actual software measurements;
3. verifies the log head's ECDSA signature against Apple's published log keys;
4. checks the release entry was unexpired at request time; and
5. (online) checks the log has only grown since your device saw it.

Honesty is a feature: entries the report gives no attestation data for are reported as not-verifiable — never silently passed. Requests handled on-device are reported as exactly that: nothing left your device, so there is nothing to check against a cloud log.

Quickstart

# with uv
uvx pcc-verify Apple_Intelligence_Report.json
# or
pip install pcc-verify
pcc-verify Apple_Intelligence_Report.json

To get a report file: Settings (iOS/iPadOS) or System Settings (macOS) → Privacy & Security → Apple Intelligence Report → set the duration to 7 days (the 15-minute default captures almost nothing) → use Apple Intelligence for a while → Export Activity.

$ pcc-verify Apple_Intelligence_Report.json
pcc-verify 0.1.0 — Apple Intelligence Report verification

Mode: online (live transparency log consulted)
Requests routed to Private Cloud Compute: 12   (plus 34 handled on-device — …)

    9  verified
       The attestation data your device recorded for these requests chains,
       cryptographically, to a software release published in Apple's transparency log.
    3  not verifiable
       The exported report contains no attestation data for these requests, …

Useful flags: --verbose (per-check detail), --json out.json, --markdown out.md, --offline (no network at all), and --save-keys keys.json / --keys keys.json to pin Apple's log keys once and verify fully offline afterwards. Exit code is 1 if anything is proof-invalid, so it can gate CI-style automation.

Privacy

Your exported report can contain your prompts and responses. pcc-verify never sends your report anywhere. The only network access is to Apple's own transparency-log endpoints (init-kt-prod.ess.apple.com and the *.apple.com hosts it advertises), enforced by an allowlist in the code, and those requests carry only protocol constants and tree identifiers. There is no telemetry. --offline disables even that.

What a verdict means (and what it cannot mean)

Verdict	Meaning
verified	The attestation chains, cryptographically, to a release in Apple's public log: valid inclusion proof against a log head signed by Apple's published key, and the bundle's own measurements reproduce the logged release digest.
proof-invalid	A cryptographic check failed. This should never happen for genuine data — worth investigating and reporting.
incomplete	No check failed, but something material could not run (offline without pinned keys, unparseable ticket shape). Not a pass.
not-verifiable	The report carries no attestation data for this entry. Common and expected — the report only captures bundles for some nodes.
unsupported	Attestation data present but in a format this tool cannot decode (likely a newer OS). Please open an issue.

Limits you should know about, stated plainly:

• The report itself is unsigned JSON produced by your device. pcc-verify verifies Apple's log commitment against what the device recorded; it cannot prove the device recorded truthfully or completely. (Verifying the device stack itself is what Apple's VRE and security bounty are for.)
• Runtime properties leave no trace in the export: OHTTP relay IP concealment, stateless deletion of your data after processing, key-release behavior. Those remain Apple claims outside any post-hoc tool's reach.
• Full SEP-attestation semantic validation (certificate-chain pinning to Apple's data-center CA, SEP register policy) is out of scope for v0.1.0; the fields are parsed and surfaced, not judged.

The full reasoning — what the export actually contains, how the log is accessed, what Apple's license permits, and why this project is a clean-room implementation — is in docs/FEASIBILITY.md.

How it verifies (for the curious)

The exported report embeds, per PCC node, an attestation bundle containing the node's software measurements (OS + cryptex Image4 tickets) and a transparency-log inclusion proof (leaf bytes, Merkle path, signed log head). pcc-verify canonicalizes the tickets exactly as Apple documents (personalized fields nulled, per-node signature dropped), rebuilds the DER Release structure, hashes it, and requires that digest to equal the one in the log leaf — then requires the leaf to hash up the Merkle path to the signed root. Log keys come from Apple's public researcher endpoints (the same ones Apple points security researchers at), discovered via Apple's KT init bag. Every protocol fact is cited to the PCC Security Guide in the source.

This project is MIT-licensed, standalone, and contains no code from apple/security-pcc (whose restrictive license prohibits reuse — see the note in LICENSE and the rules in CONTRIBUTING.md).

Related

• Apple: PCC Security Guide · Security research on PCC
• Same author, same "verifiable trust, not just a claim" philosophy: provably-local (verify a developer's app makes no network calls) — this project targets Apple's cloud instead, and shares no code with it.