Marcos Balter (born April 1, 1974) is a Brazilian contemporary classical music composer and the Fritz Reiner Professor of Musical Composition at Columbia University. Life and professional career B
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 0xebe83f5be51374d811091dcc18a31f3073762e0f3cddb3ff8502e4da8da98987. Chain 2 (Bitcoin): anchored in block 954587 (2026-06-20T19:10:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bc5d1dba-99ec-4e19-a806-8e57359d4db4.json and https://artists.proofprofile.net/proofs/artist/bc5d1dba-99ec-4e19-a806-8e57359d4db4.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 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 0xd453cabaf9c403765a3c77f747911bb9241398a8d6fd48dbf3767eacb5354326. Chain 2 (Bitcoin): anchored in block 960362 (2026-07-31T06:58:00Z), 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/QM8K52400205.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb8e72b6936ebcf48bf3b02933168a20593055925ed6152d6e091b03847c6be1c. 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/US7MN1600674.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa751f56ae48ee888eed2fb4beddb3afd26db4a0a0fb9dfea9c220a99f62fd457. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/US7MN1600675.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd694817c18a8bcf74ea2af9a336ab2140d7d01186b78e3037136bfb2e730fb3f. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/US7MN1600676.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfe0fa3c95f98f4eb12d50d28de6de28ff6298e295765b738910cecdd0edfbce5. Chain 2 (Bitcoin): anchored in block 960485 (2026-08-01T00:10:46Z), 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/US7MN1600683.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf317a7bad6dfb00a9cdddd461e0de129e7cfd70d03fe62c14de03ef7045e0de2. Chain 2 (Bitcoin): anchored in block 960509 (2026-08-01T04:30:37Z), 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/US7MN1600684.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9234d3a0a758caa9da8b270c90297f7ca49f04132c6a48d65151a6d15ba65d78. 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/US7MN1600685.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc443b67f95f2fcbe0c8f4686bec76106ea44dfbe6029425edfba82622101c91a. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/US7MN1600688.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x674931f866da6d08fd6c59bb65e78cdc73c1a08f5eb251cbce838eaf5fe07be6. Chain 2 (Bitcoin): anchored in block 960095 (2026-07-29T11:07:37Z), 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/USQY51622606.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x524aaea42711d687b8a298f5a9653ecb26ef218b684e735c61722941957f97c6. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/USQY51622607.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbbe018cfb7a2eee4f9081dfa2a9a0835ac0089ca8bfc345468b645529aa8359d. 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/USQY51622608.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x28306bd622c40e85f612eea5801d41557c534cf39573d50e3f6fd8a17048f6c9. Chain 2 (Bitcoin): anchored in block 960389 (2026-07-31T10:20:10Z), 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/USQY51622609.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0b28aa4e548a95857bac3a33b759629dd54e553fcae036cea4b07381a4317954. 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/USQY51622610.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x673b050542b54b271051662de0f17e249ad3cb729a1ba2c36b660da39b8e4089. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/USQY51622613.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9070953a9b3f8ffacc9478a46b5dd763c8e1e6bd026afde6bf0bfd6d3c1b3594. 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/USB8U1064172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4cde2fc7e9e658f4a3044f6b0520f7edf16fb7de7b5bf435e4f473900cc52a7a. 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/USB8U1064173.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0b5ffbcab831436a591a05ed78c8b75529d341c46aa34976d621636f77318c09. 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/USB8U1064177.