Satohash — Bitcoin document stamping

Blockchain for Archives — Long-Term Records That Can't Be Altered

Archives, libraries, governments, and companies all face the same problem: how do you prove a record is authentic and unchanged, decades after it was created? Bitcoin timestamping is quietly becoming the answer.

The archivist's problem

Traditional archives rely on:

• Chain of custody — paper logs that can be lost or forged
• Trusted institutions — a library or vault that could, in theory, be compromised
• Hash-based integrity — checksums stored alongside the data they protect (a thief who alters the data can alter the checksum too)

Every one of those has a weakness. Bitcoin changes the game because the proof lives outside any single institution's control.

How it works for archives

1. Hash each record (or a manifest of a whole collection) → SHA-256 fingerprint.

2. Anchor the fingerprint to Bitcoin via OpenTimestamps — a tiny commitment in a block.

3. Store the .ots proofs alongside the records (in a separate, offline location).

4. Re-verify anytime — recompute the hash, check it against the block. If a single byte changed, the check fails. If the check passes, the record is byte-identical to what existed before the block.

Why Bitcoin specifically

• ~18,000 independent full nodes — no single point of failure or control.
• Never rewritten in 15+ years — the longest-running public integrity anchor on Earth.
• Verifiable by anyone — a court, a researcher, or a citizen can check without trusting the archive.
• Timestamp is global — the block height is a universal "as of" date, not a local server's clock.

Real-world fits

Best practices for archives

• Stamp manifests, not just files — one manifest hash covers a whole collection.
• Keep .ots files offline — in cold storage, separate from the records.
• Re-anchor periodically — if the protocol or calendars evolve, re-stamp.
• Document the process — a written policy makes the timestamp admissible as evidence.

The honest caveats

• Bitcoin timestamping proves integrity + existence at a time. It does NOT prove who created a record or that it's true — only that it hasn't changed since the block.
• Records must be stored somewhere the archive controls; the timestamp proves they're unchanged, not that they'll survive.
• For maximum admissibility, pair with institutional policies and, where needed, qualified electronic time stamps (eIDAS).

Anchor your archive today: satohash.io/stamp