thumb|upright=1.4|The Norman () keep of Rochester Castle, England (rear). The shorter rectangular tower attached to the keep is its forebuilding, and the curtain wall is in the foreground. A keep is a
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x77dbecaf0b3bd19d252fa1db4fe935fc7303098a14d0b6291a347f0b326273cc. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a49e0a37-0421-459b-8019-52a0f7db2d2c.json and https://artists.proofprofile.net/proofs/artist/a49e0a37-0421-459b-8019-52a0f7db2d2c.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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x896ddb8d5be09967f02329269f5112c1506b028c069f25cbb26d420787998277. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZFZ42306407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9ccf8c5117450e4346198f21db0e760b74470cdb0cc63f56eb1d0558b415aae. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/QZFZ42306408.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa537f17eda1850624a6a4a0347080a8e2d7c5ec87465955e243acdbb569fb759. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZFZ42306410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x86aa1ffec7d52f36d731795c6f8518d68ea5c3888ecdae624ff9cf3fb1e295a9. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZFZ42306411.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe923290a183d40b2e660b838b8d09b220504e9ceac17f7c513b4ed0e8e9e0b72. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/QZFZ42306412.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a9e7da8d05614821a335b5aaf29c9fb004fc62a1d5bc6a4fe3b83f8973ed8ee. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZFZ42306413.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb76fbea196f85e11820ff2a97179f52c9ec840e76e9c205f62c6fec23a4be56. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZ8LD1793082.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xffb007f2dfdd3c9ef1aa358453c015291368a7f191f64c4bb89909c9ba937c30. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/QM4TX2599493.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fbcff50c0c4c14ca0d766a91b0e6ca8e71948664c245f7fe4c864afdc0374df. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/QM4TX2592516.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fbcff50c0c4c14ca0d766a91b0e6ca8e71948664c245f7fe4c864afdc0374df. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/QM4TX2592516.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb569e26c5b182c0ce933d04543570b7d19273c5af445abebec63357a49f7208. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/QZK6J2312690.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc8c2bcc5aeba4571eef037b2d1d067ff3b521dfa9ffb1b72401ccfa487f4a215. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZFZ62077086.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x870118c2e5d988094f4a723358320668205dd4ab93d8979ae17a7cb0ef061004. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/QZ8LD1793491.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c2f9369302ce8fb57ad077d9dd65195900889b4e0de7a393d058143ce1f1830. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/QZ8LD1793492.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4aeb118ffc6cdc0e9755c9ac2860a98b12a9cdba9ad00a24d0e438d95c125963. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/QZ8LD1793493.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa23eb7fc1fcfa0088e5beca53846dfe2d2b6d28890dcf94d0d1359c53b2e85a7. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/USA2P1601828.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb8c1782e03c340f42bb1764311ad5f8ad6f4dff43ab589791a2c0ba149598c8. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/USA2P1601829.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1be6d1d369e1d8c1db860d0e4f62efc6a8cfd46cdb7bf426fb15b13ab6f45419. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/USA2P1601830.