Seyfullah Sağır (born 16 March 1998), better known as Sefo, is a Turkish singer, songwriter and rapper. He rose to fame in Turkey with his song "Bilmem mi?", which features reggaeton elements. Life 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 0x7f10a0558156a46abf6cde4b63f998b3c575dd8d7277b7733759b67f1a03f57d. Chain 2 (Bitcoin): anchored in block 953889 (2026-06-16T04:57:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0e708501-6feb-437a-a9e9-2a1b727a8074.json and https://artists.proofprofile.net/proofs/artist/0e708501-6feb-437a-a9e9-2a1b727a8074.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 0x00f11d40a9bdf79a82cd426703c9ae0ef4389edf6b2e06e17634d0c6c3dfe1d9. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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/KSB032501106.