Warrant canary

If this page stops updating, something is wrong.

The warrant canary is a monthly attestation that Sign has not, as of the date below, received a legally-binding request that would compromise customer trust in our receipts or audit log. If the canary disappears or stops updating, treat it as a signal: something happened that we were compelled to stay silent about.

As of 2026-04-17, Zoza Sign has:

Received gag-order warrantsNONE

Received National Security LettersNONE

Compromised authority private keyNO

Issued duress receiptsNO

Applied silent log-rewritesNO — chain integrity verifiable at /v1/audit/verify

Audit log head hash on this date(fetch in progress)

Authority pubkey fingerprint(fetch in progress)

This statement will be re-signed monthly with the Sign authority key. Previous canaries + their signatures are in the audit log under action=authority_rotate. Re-issued on the 1st of each month. Next update: 2026-05-01.

Why a canary

Some legal regimes (FISA orders, National Security Letters) prohibit the recipient from disclosing that they received the order. They don't prohibit the recipient from stopping to affirm that they haven't received one. A canary reverses the default: we continuously affirm the negative, and the absence of that affirmation itself becomes the signal.

This is a hedge, not a guarantee. A legally sophisticated adversary could demand we keep lying with canary updates. The canary is one layer among many — it pairs with Sign's public audit log, authority pubkey pinning, and offline receipt verification. All four must be compromised simultaneously for an attacker to forge receipts undetectably.

What to do if the canary is missing

Stop accepting new receipts issued after the last valid canary. Rotate your pinned authority pubkey to one derived from a canary-aged snapshot.
Re-verify your stored receipts against the historical pubkey in the audit log. Receipts older than the canary gap are unaffected.
Check the Sign audit log head hash — see sign-audit. If the chain fails /v1/audit/verify, that's a second independent signal.
Contact us through unrelated channels. Email + Twitter + Slack all simultaneously going dark is itself informative.

Scope

This canary covers Zoza Sign only. Separate canaries exist for:

Shield canary — wallet protection product
Auth canary — crypto authentication product
Vault canary — encrypted fields product

Cross-product compromise (one canary flipping while others stay green) would itself be a signal.

Canary discipline: updated monthly, signed by the current Sign authority key, head hash anchored to that calendar month. Automated re-signing is explicitly avoided — each canary requires a human-reviewed action to preserve the signal.