The Letterbox

Recording identifiers

ISRC

USFM91100301

CopyrightID (CopyrightChains transaction hash)

0xbe8a372427c1541437c9eeec111fd0fa011d09288b9e2172267e3a3c541f1489

Copyright registration time

2026-06-26T13:04:18+00:00

OpenTimestamps proof evidence

Bitcoin-attested timestamp

2026-07-02T03:55:08Z

Bitcoin block

956304

Canonical record hash

sha256:1789a120d568d4c412fa5fcf93d817808512ba57e89f6b39c031f2103146a0d9

• Verify the CopyrightID on CopyrightChains
• Verify the Bitcoin block independently
• Read the machine-verifiable OTS result

What this proof establishes

This recording belongs to ProofProfile's historical evidence base derived from the pre-2022 AcousticBrainz and MusicBrainz corpus. ISRC is the stable recording-level bridge from that source corpus to the authoritative cc-db-prod track record.

CopyrightChains and Bitcoin OpenTimestamps make the exact committed record independently verifiable today. The cryptographic proof does not by itself establish authorship or ownership of the underlying recording.

Read the complete pre-generative-AI provenance and verification method.