Prosa is Norway's largest literary magazine. The magazine is published on a bimonthly basis and has been in circulation since 1995. History and profile The first issue of Prosa was published in 1995.
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 0xc3d2149cc0eecee0a5c82d2037ad4dcde8191beaf470f6d5b6b7239a6da8dc7b. Chain 2 (Bitcoin): anchored in block 954043 (2026-06-17T04:15:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3ed40e8d-40c9-4eb1-a271-cea501d59a86.json and https://artists.proofprofile.net/proofs/artist/3ed40e8d-40c9-4eb1-a271-cea501d59a86.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).