thumb|The Polytech Choir and artistic director Saara Aittakumpu in 2017 The Polytech Choir () is an academic male choir established in 1900. The majority of the choir's members are engineering student
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 0xcd790649f7f9b89aa80962c703779f61f77b5b991be8296fc079fdf458ed3ff4. Chain 2 (Bitcoin): anchored in block 953765 (2026-06-15T08:55:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bd49bf96-41a6-4d4a-8c0e-08d395c4d073.json and https://artists.proofprofile.net/proofs/artist/bd49bf96-41a6-4d4a-8c0e-08d395c4d073.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
20 Suosikkia / Muistoja Pohjolasta / Valkoisen Suomen lauluja
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 0x535f2393148a73b5d33587f0ac2df0d0b0d4d4f16c0f72781a79713c8a219730. 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/FIFSC7000048.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6a201d3463950266a572ff5394945695f32e2fd0b0b05c321f5bc061fd6865b. 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/FIFSC7000039.
Kilpinen / Arr Heikkilä : Siniristilippumme (Flag Anthem)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc7a1d2e36d8363f8ad7f499eb0081770f6d5b2f5d1eab84431a2d578ffc51d7f. 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/FIFSC7200024.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa8c5a9d8ebab3960e1a49e683111f562d852de5a2cfac56244103e7746a7d06b. 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/FIFSC7000040.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfed10ea5e573611382a57457e70a1f3a92b064b3b9f91002d09e997d4d834d90. 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/FIFSC7200026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6d54c5dec3ec0e5c25a95b6f4fbaff6961e61dcea82eaea5048bc6afa78aaafe. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/FIFSC7000013.
Trad / Arr Heikkilä : Olet maamme armahin Suomenmaa - Thou Art Our Land, Beloved Finland
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb5fa391816cb2f8cf9d6e7dd9da0b4b9ba0c565570a23898a3abeb26612a0a0. 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/FIFSC7200021.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x781e0868ed11037e83ce46b47dcd1af43c70f9923578f06e9a99288539ff694f. 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/FIFSC7000041.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0452f10df8fb2aef31812327b38a3ca30e35300648fd38cc8e21272c4c42b7b6. 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/FIFSC7000042.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe2b0cef68cc62c1eae7d1fd31052c8eeea8d6bfb291c5b01876121b9384d341b. 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/FIFSC7000045.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xced0e2a8789a2d246410ffba2701ccffe2194ed6079d0a5bd059934168d727f1. 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/FIFSC7000043.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37d5ad6e91eee1361405fa2ced3748fc4d1226a29e0577beed7c1885d6b14429. Chain 2 (Bitcoin): anchored in block 960258 (2026-07-30T12:45:34Z), 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/FIFSC7000046.
Pacius : Laps' Suomen - Child of Finland
Children's Ensemble and Olli Heikkilä Orchestra
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x617ab412505238727cf7dc0ab407e9b863c4a99a741deb0c71d8c524b38557c0. 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/FIFSC7200031.
Kress / Arr Heikkilä : Porilaisten marssi (March of The Pori Regiment)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x18010407423d978274ae6be454a51e485d3c111795b982303f1f0bceb286b3d7. 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/FIFSC7200032.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x733a2f0bcc376b4d4248434ae28bb2dea19ae75295de3a8f97e952d7e125341a. 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/FIFSC7200022.
Trad : Kotimaani ompi Suomi - My Homeland Is Finland
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe2c92f8360ba659e433ae89abd89cb3260e57b6f54cf535c3552616302027ae0. 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/FIFSC7200025.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xea56657e4e5dcc178da269c8dbfd966778fa14fe968f7bf6f23c8f2f2be03299. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FIFSC7000044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05024b5ced9894b927bf3540bc748962ad75400ecc4abea461bc253472bde53b. 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/FIFSC7000047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb5fa391816cb2f8cf9d6e7dd9da0b4b9ba0c565570a23898a3abeb26612a0a0. 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/FIFSC7200021.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5dfd859071c85a90573dc13a17ccae2b05e81bb11d61883b458d9fac4127ddb0. Chain 2 (Bitcoin): anchored in block 960381 (2026-07-31T09:50:11Z), 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/FIFMF1221693.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x18010407423d978274ae6be454a51e485d3c111795b982303f1f0bceb286b3d7. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/FIFSC7200032.
Muistoja Pohjolasta - Valkoisen Suomen lauluja
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6a201d3463950266a572ff5394945695f32e2fd0b0b05c321f5bc061fd6865b. 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/FIFSC7000039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfed10ea5e573611382a57457e70a1f3a92b064b3b9f91002d09e997d4d834d90. 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/FIFSC7200026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0452f10df8fb2aef31812327b38a3ca30e35300648fd38cc8e21272c4c42b7b6. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/FIFSC7000042.
Schubert: Works for Male Choir a cappella