Problemas () was a monthly political magazine published in Rio de Janeiro, Brazil. It was subtitled Revista Mensal de Cultura Política. The magazine was first published in August 1947. It was the offi
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 0xf50754d0400f2310002ca555f7f3b35a74faf228dc68273b8efb67e3efb03187. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e0eedc6b-c9d5-47aa-ad58-977882cfc033.json and https://artists.proofprofile.net/proofs/artist/e0eedc6b-c9d5-47aa-ad58-977882cfc033.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).