CoSy, short for Conferencing System, was an early computer conferencing system developed at the University of Guelph. The CoS software grew out of an interest in group computer mediated communication
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 0x5486b09cb5a26793196388d5621c77fda267c5f4d5e5645930a9d868719523e4. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/614e043d-b8f6-4d8d-8b2e-5801157889d9.json and https://artists.proofprofile.net/proofs/artist/614e043d-b8f6-4d8d-8b2e-5801157889d9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).