De Hardheid is a Dutch skapunk band from Amsterdam composed of nine members. The band was founded in 1996 and sings in Dutch. De Hardheid has released three studio albums and one EP. Although the ban
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 0x5bc293caaba17e52d9185f509ed1ee75c4866637d0059bd748f1c177c5bde00f. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/70766f1f-ff6b-4990-b6de-a5b806924d37.json and https://artists.proofprofile.net/proofs/artist/70766f1f-ff6b-4990-b6de-a5b806924d37.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 0x07e43a09f5e67f410e10316dbcf47a059468004ba06f602ce9b0bc798eb3ca4b. Chain 2 (Bitcoin): anchored in block 958228 (2026-07-16T02:46:47Z), 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/GBSMU2359039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ac720d868badeb6e6a21d8835056dec6fb2af129e5c2f8f7cb24079551a3371. Chain 2 (Bitcoin): anchored in block 958079 (2026-07-15T00:21:05Z), 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/GBSMU2359040.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb25d33a72099c6f6e4b42cb29638bc8eed61485ac0b6833271166142e6383245. Chain 2 (Bitcoin): anchored in block 958152 (2026-07-15T13:56:39Z), 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/GBSMU2359041.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde1f87416368e1d045d61ff868042bd82fab479b0416f9f09f86c7418b7eb1bb. Chain 2 (Bitcoin): anchored in block 958568 (2026-07-18T15:23:47Z), 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/GBSMU2359042.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8839c877b41236ef0b6a0fdfb280f1e8203a9343c67b66d63d6b32b510e7b128. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/GBSMU2359045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa745b97d6681d93baee7a64dcd7aedc58daf382aac710fb77925ac5be4b3c893. Chain 2 (Bitcoin): anchored in block 956790 (2026-07-05T12:31:54Z), 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/GBSMU2359047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe707c02a1d7f5e00f4a5cf7897430bac50553a32ceec055b62185c140c93811f. Chain 2 (Bitcoin): anchored in block 958430 (2026-07-17T15:33:28Z), 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/GBSMU2360501.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0dc9d5154ac6ba28f5f3f149f960902dbed2a3e005033b4484bfc799f07c9c16. Chain 2 (Bitcoin): anchored in block 958728 (2026-07-19T12:24:55Z), 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/GBSMU2360867.