Da, DA, dA and other variants may refer to: Arts, entertainment, and media DA! (band), a Chicago post-punk band of the 1980s Da (play), a 1978 play by Hugh Leonard Da (film), a 1988 film based on the
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 0x28fab4915fc94b51e05eeede233cc85ef6e4aa0fa0e6833ba2385b114f556df0. Chain 2 (Bitcoin): anchored in block 953892 (2026-06-16T05:01:46Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0e79863d-c779-4473-a0a8-e7fc9c1465be.json and https://artists.proofprofile.net/proofs/artist/0e79863d-c779-4473-a0a8-e7fc9c1465be.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 0xc42e3b2d9cae96f9292d45a5866a2c2a61e6a7a14024810e8c59abe5e37ec68e. Chain 2 (Bitcoin): anchored in block 958041 (2026-07-14T18:13:17Z), 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/QZES62167582.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x54494fb5dacd19b155aaf4b8452b05dcb42f07aa678c379943f6c202e98f5d60. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/QZES62167586.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29aec7eda53b07817f31f6a1ec6f99cd920072af8ae0268285cf6afbd315246f. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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/QZES62167590.