thumb|right|300px|Kurt Schwitters, Das Undbild, 1919, Staatsgalerie Stuttgart Collage (, from the , "to glue" or "to stick together") is a technique of art creation, primarily used in the visual arts,
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 0xcb18b073b92a10d5bb383a0526ff40405c112c12e81aaba74b706a637d5cd8c2. Chain 2 (Bitcoin): anchored in block 953742 (2026-06-15T04:47:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/76a620fb-42f2-4d07-a5fa-bc4b8216e59d.json and https://artists.proofprofile.net/proofs/artist/76a620fb-42f2-4d07-a5fa-bc4b8216e59d.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 0x7d8c7a0d53500c190edb3263eb18f20e0d184727b38e465daffd44be0dbba197. Chain 2 (Bitcoin): anchored in block 958146 (2026-07-15T10:33:22Z), 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/PLB822200153.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5da0fd29d8d0cb4014304ca6ea3a9b7d3fef3006d4b0a27d9a0e100f54937328. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T19:17:28Z), 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/PLB822200101.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb681df2ab1085db4aabb5a7c54f6393ab02dbcc5e39b36e7a95fbfa1e5e95b52. Chain 2 (Bitcoin): anchored in block 959001 (2026-07-21T11:41:42Z), 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/PLB822200102.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xab54e8270b9d02d25e0ff59b22b9304abbb4ee33939cafa2dfedd2b0d6a922c0. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/PLB822200103.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3096066dc6bf0e49ed5f02ce06ed84399ebf752914189880541c4a8b77720041. Chain 2 (Bitcoin): anchored in block 958104 (2026-07-15T05:34:05Z), 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/PLB822200105.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbd9967396412701b7b4246a85bb5303013a57bfb219f3522846fb5df531019c9. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/PLB822300112.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaa485d61e698b6c5b032e32dea30fd4ed5002ddfec33a689414c4e0c68099930. Chain 2 (Bitcoin): anchored in block 959084 (2026-07-22T00:50:00Z), 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/PLB822300113.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x51173f5027d1389975a16ca0a0a0ea5ac61c40d2e3afe6fe52a88052da5dc01f. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/PLB822300115.