420 may refer to: Science and technology 420 (number), in mathematics 420 Bertholda, a main-belt asteroid 4:2:0, a chroma subsampling layout Cannabis culture 420 (cannabis culture), informal ref
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7fadb875e254b7868b728bbb2d061b4f68b56d06d5ebe78c08f187c17123d60f. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6c2838e5-ca90-4d5d-b342-477d3168193c.json and https://artists.proofprofile.net/proofs/artist/6c2838e5-ca90-4d5d-b342-477d3168193c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdb20659b1675f0c4069a8d9cf3982ecf7161fc3432d4a1756605bef7662007a0. Chain 2 (Bitcoin): anchored in block 958316 (2026-07-16T19:42:29Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USYBL2001391.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x843f48255973e9ef46935f8b49158dd8e43b939c6a6b01fd7eb58defbaaa8155. Chain 2 (Bitcoin): anchored in block 958627 (2026-07-18T23:33:54Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USYBL2001392.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d6eb5b5af11861f582a10afc5b2d37cd998495b0c6df75959972744f273b264. Chain 2 (Bitcoin): anchored in block 957826 (2026-07-13T08:56:09Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USYBL2001393.
Don't Talk to Strangers: The Features, Vol. 2
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc79f7b0fc48a00a090d49f344d0e8cda1b1c31a3412b3f73b72c73cd935ae094. Chain 2 (Bitcoin): anchored in block 960456 (2026-07-31T19:53:57Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QZNWT2067030.