Old City often refers to old town, the historic or original core of a city or town. Old City may refer to several places: Historical cities or regions of cities Africa Old City (Cairo), Egypt
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 0x92e0a3599163fa48cafc7238222b1892c6c00ed99699734bfe744b24d0217088. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/516c44fd-65e1-4c55-8cdf-ce9ea1b85c32.json and https://artists.proofprofile.net/proofs/artist/516c44fd-65e1-4c55-8cdf-ce9ea1b85c32.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 0xea5a0133098e7001ffc5a16d23a7e663badedd7e4d544f0e0a749284b23649f3. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USA2B2402088.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x13d67b3d560ed223ea7781a731f01b7e874907ca7eb900d9acff194012bf7df8. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USA2B2402079.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb481cd9296a64b9672191d2caf21c8f7011cbf146bf809cd9e95fe9ed768b56. Chain 2 (Bitcoin): anchored in block 960179 (2026-07-30T00:39:11Z), 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/USA2B2402080.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5bd3fb4c58abf7e8bb50f17824895e03784c0bc61ae4da1000dff20ca63d4872. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/USA2B2402081.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfbb76fe3e939c8a943044c8791ae6ff0aab858d56316ff69711f5ef7aea671b6. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USA2B2402082.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x47558e342cf401a7aba8da08ddc52f7e151f1bc3ad91dc30f50a99bfd8ff1581. Chain 2 (Bitcoin): anchored in block 960209 (2026-07-30T05:15:54Z), 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/USA2B2402083.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x87632a6b999edd532c31bd31604419244ccd64a2dd12a62bc742e89c9d5534ef. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/USA2B2402084.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2023d5ccce3584655717b61ff91839586fdceb04678a9add353dcc6c6c0f856c. Chain 2 (Bitcoin): anchored in block 960296 (2026-07-30T19:11:09Z), 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/USA2B2402085.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc2bca8b301b76f5965de0e1881d0355e3214b2f9581da11d9414bc3f9a132c65. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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/USA2B2402087.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf0fdffc2ec83a302f6751605714eef22706d02b91f6728e282512302174bf90e. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/USA2B2402089.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a8ea7a0bed5b878429e4fb6ed73777420e9ecbe29fbdf5632c6d699661a190a. Chain 2 (Bitcoin): anchored in block 960404 (2026-07-31T13:06:57Z), 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/USA2B2402090.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x56e85ba8e3d7c52aaa2dfc7b1da9792b054188c3db49c547217365f5af69fd48. Chain 2 (Bitcoin): anchored in block 960404 (2026-07-31T13:06:57Z), 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/USA2B2402091.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6aed8bb3a24d292c6fef8e91db3fb1f7ba005d86e18e881bce7edcf36ee42b80. Chain 2 (Bitcoin): anchored in block 960497 (2026-08-01T02:22:04Z), 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/USA2B2402092.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfd0e3862c4fe027355bd843f9a4c07ac981ef9e91fd965e6c1fbee652accbf69. Chain 2 (Bitcoin): anchored in block 960468 (2026-07-31T21:25:57Z), 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/USA2B2402093.