FlightBriefArchive daily seals

Every day the FlightBriefArchive crawler lists each visit it made in a manifest: the address, the time, the result and the SHA-256 fingerprint of what it saved. Each manifest names the previous day's fingerprint, so the days form a chain. The manifest is signed with the archive's key and timestamped by two independent services: OpenTimestamps, which anchors it in the Bitcoin blockchain, and FreeTSA, an RFC 3161 timestamp authority.

The manifests stay private, because they name the pages the archive watches. This page publishes only each day's fingerprint and its proofs. When a copy is shown later, its manifest can be checked against the fingerprint here and the proofs show it existed on that day.

Asking for a copy

If you need to show what a public drone-industry page said on a given day, such as a list entry, a tender notice or a company statement, write tocontact@flightbrief.news with the address and the date. We will tell you whether the archive holds a copy from that day and which proofs come with it.

Checking a seal

With a manifest file and the proofs for its day:

openssl dgst -sha256 DAY.manifest.tsv
openssl ts -verify -data DAY.manifest.tsv -in DAY.manifest.tsv.tsr -CAfile freetsa-cacert.pem
ots verify DAY.manifest.tsv.ots

The first line must print the fingerprint listed below. FreeTSA publishes its certificate at freetsa.org; ots is the OpenTimestamps client.

Seals

38 days, newest first. Days are in UTC.