Warrant canaries explained
Answer
A warrant canary is a signed statement that a provider has not received secret legal demands, republished on a schedule. Its absence signals what the provider is prohibited from saying directly. The legal theory — that compelled speech is harder to order than prohibited speech — is untested in most jurisdictions.
The mechanism
Some legal orders come with a gag: the provider must comply and must not disclose that the order exists. A canary inverts the problem. The provider regularly publishes a signed statement that no such order has been received. If one arrives, the statement is not renewed. Nothing is disclosed — something simply stops happening.
The theory is that compelling a company to actively publish a false statement is legally harder than prohibiting it from disclosing a true one. In most jurisdictions this has never been tested, which is the first thing any honest page on the subject has to say.
What makes a canary credible
A cryptographic signature, so it cannot be forged. A fixed schedule, so absence is unambiguous rather than ambiguous. A recent external entropy source — a Bitcoin block hash or a newspaper headline — embedded in the text, proving the statement was signed after that date rather than pre-signed in bulk.
Without the entropy source, a provider under duress could hand over a stack of pre-signed future canaries and the mechanism collapses. It is the single detail that separates a real canary from decoration, and most published canaries do not have it.
- PGP signature with a published, verifiable key
- Fixed publication schedule — ours is quarterly
- Recent Bitcoin block hash embedded in the signed text
- Explicit list of what the statement covers
- Prior versions archived and independently mirrored
Verifying ours
Fetch the canary at /canary, import the key published at /pgp, and verify the signature with gpg --verify. Check the embedded block hash against a block explorer and confirm the block was mined on or after the stated date.
Check the fingerprint against the copy on our contact page and against any independent mirror you can find. A key you fetched from the same server you are trying to verify proves less than you would like.
What to do if it lapses
Not panic, and not ignore it. Canaries lapse for boring reasons: the person who signs it is on holiday, the schedule slipped, someone forgot. A single missed cycle is weak evidence.
A canary that lapses and is then quietly renewed with different wording is much stronger evidence, and so is a lapse the provider will not comment on. The correct response to a genuine lapse is to move data you cannot afford to have disclosed, not to assume the worst about everything.
Frequently asked questions
01 Do warrant canaries actually work?
Legally, untested in most jurisdictions. The theory that compelled false speech is harder to order than prohibited true speech is plausible but unproven. Treat a canary as one signal, not as proof.
02 How do I verify yours?
Fetch /canary, import the key at /pgp, run gpg --verify, then check the embedded Bitcoin block hash on a block explorer to confirm it was signed after that date.
03 What if a canary is not renewed?
Treat one missed cycle as weak evidence — schedules slip for mundane reasons. A lapse followed by quietly changed wording, or a lapse the provider will not discuss, is much stronger.
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