Marko Topchii ( ; born January 7, 1991) is a classical guitarist from Ukraine. Topchii has won more than 100 awards worldwide in the international classical guitar competitions in the professional cat
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 0x17d2cdd2c83bae0b4f2e20a7ca47185c3d1554464d53e2d33b982531ff983693. Chain 2 (Bitcoin): anchored in block 953812 (2026-06-15T17:06:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f77120ee-c800-43f1-9762-55258aaa1feb.json and https://artists.proofprofile.net/proofs/artist/f77120ee-c800-43f1-9762-55258aaa1feb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Barrios Mangoré, Konstantin Bliokh & Others: Guitar Works
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 0xf5b753bdb23fdd75398d7824172ffc4b647e7512e53a238465a30329d67cc723. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/HKI192407601.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3e341a31085c1e773a214c449d0fc2cff950dfc610c31bc4135ba7bac0cd8b8c. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI192407602.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x621685bd737ccf3dd649dfb59f198658e0b1c6fe813715fcf72d944b8ff10e03. Chain 2 (Bitcoin): anchored in block 960311 (2026-07-30T20:45:02Z), 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/HKI192407603.
Studi di virtuosità e di trascendenza: No. 18, Rosario
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4347c266256b3563c4619ae622bff1077c3923a83d92966fa427203273d02f7e. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI192407604.
Studi di virtuosità e di trascendenza: No. 32, Embarquement pour Cythère
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x08c704585066495a188ded48224fcc9e4b89d524ef6dacee75ce8a902de9900a. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/HKI192407605.
Studi di virtuosità e di trascendenza: No. 19, Jondo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd25fbc1aa1d12dee67c6edcb75aa671ed1e09cf5aaf833ea816f9daeea8a774c. Chain 2 (Bitcoin): anchored in block 960404 (2026-07-31T13:06:57Z), 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/HKI192407606.
5 Hommages français: No. 5, Hommage à Ravel. Comme un hommage
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfbeb1cbf5ecc1a50ba98a10f23497d7076af583cc804a8ce1d6e06022bb531d2. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/HKI192407607.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabfca952f28199f0d92c287e9106e4ccd353c69228cb0ba9dcd89427b08e0fc4. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI192407608.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc5cda12ebf11adb1cb192ba3fc619ff8422bdec5ab6d7904d0c21d3ae0ea204e. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/HKI192407609.
A Closed World of Fine Feelings and Grand Design
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x118d9cd3e6b5ff1c7f4c733ec657cb5b01d1dfb1e6082cfef936d172834fec14. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI192407614.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xae934e41b027ccdd64d987d14c46343ab24471a6b414c6c9a0853d53324c194a. Chain 2 (Bitcoin): anchored in block 960220 (2026-07-30T07:28:30Z), 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/USB8U2202054.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xec84b369681f7c4ceb4494fc970967b3e701b7e31f474fe85a736718817e5d42. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USB8U2202055.
Pièce en forme de passacaille for Guitar
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7cbbb3972593aa970ac99846281ad63023c83112174df56302d36c2949a05157. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/USB8U2202056.
Variaciones sobre el Carnaval de Venecia de Paganini
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x833facfa8ea0cd069e95c01e6c87b91114af600878277f4e96e62e66e98a80f9. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USB8U2202057.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfca99fa56bf0fa28586f0996b40b16d94239cd5ec8aeb2f4f01e755a87ab4053. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/HKI191810001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6a18c24b2a80a7bfefd44c5656f9dc95353917089feb2271e4e87eea57fafc0e. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI191810004.
Capriccio diabolico, Op. 85 "Homage to Paganini"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x605e9e8b37ae8f2b070a54e58f17578e37537cfc382b5c713ca000394b203f1a. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/HKI191810005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xffc92de5bcc260b37da99620b6dc8ade998ddf0c74be9af7e17f906e34f272d6. Chain 2 (Bitcoin): anchored in block 960494 (2026-08-01T01:44:32Z), 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/HKI191810006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7308c2609c9f44f80ff5d454f988c8ee9ea0b2fab47c59b28abe2c26a3b20980. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/HKI191810012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8dc8600e8a81d0a6c868bc5ebf2bb60d81b8f53708ce385541fd118c0d9710e1. Chain 2 (Bitcoin): anchored in block 960266 (2026-07-30T14:44:50Z), 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/HKI191810014.