PZK may refer to: Polski Związek Krótkofalowców, an amateur radio organization in Poland Polish Cycling Federation (Polski Związek Kolarski), a cycling organization in Poland
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 0xcfea34ada179c8c77aeeb872ae645c1d1d637f00da2b6668c79657a1a08eba47. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/81078ec1-1f13-4f8d-93d1-19b3c409fcce.json and https://artists.proofprofile.net/proofs/artist/81078ec1-1f13-4f8d-93d1-19b3c409fcce.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 0x1acdbe9edf12eb56c0dfff93f1ae5b8fd9b7a418ce3618b8f016a2246082261e. Chain 2 (Bitcoin): anchored in block 958996 (2026-07-21T10:57:35Z), 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/FRZ040900238.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x910720e63814ecdb27577943a247d0775fc3ec98496e5cba5d9e5d8ccd546a38. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/FRZ040900240.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5547ea508c6ce3b602dcc2db418b8d5e48d27e156f985c53691ef0cdc8f8bdda. Chain 2 (Bitcoin): anchored in block 958322 (2026-07-16T20:44:14Z), 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/FRZ040900243.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4aa711940c73d0c1ad57ef71f9d17bf08e164231b36b1f1ff0d16c02cbba9a8c. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/FRZ040900247.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd44ceacf576473b71158fb1ed78edd5b863a427b1009e39cc91de181336b2269. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/FRZ040900248.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc00a7bf6385c1f56c463a030a22c563409b4b979964e4fbd4d7366fefea8c0bb. Chain 2 (Bitcoin): anchored in block 959096 (2026-07-22T03:48:36Z), 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/FRZ040900285.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb045c32b26519afd239c7bda68b1a9cf9b0659033a7a2780d673a8d3cd2aa3c7. Chain 2 (Bitcoin): anchored in block 958436 (2026-07-17T16:42:22Z), 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/FR2Y31200003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x844f5a5dfa4b03e75cc2511487c766c0aa333ae6a109244d599f7217a3772e24. Chain 2 (Bitcoin): anchored in block 958468 (2026-07-18T00:27:51Z), 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/FR2Y31200005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8ecb0529e914edf55f768a0cfebc04005ffb3cff726069598623a89503715fc5. Chain 2 (Bitcoin): anchored in block 959088 (2026-07-22T02:14:33Z), 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/FR2Y31200002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d9b0f01e6475db3e35696ead714a31cf7b513b679793b7c852f0e4ac533518a. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/FRP9W2100960.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d9b0f01e6475db3e35696ead714a31cf7b513b679793b7c852f0e4ac533518a. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/FRP9W2100960.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7754d99932e62dfe321a8e6bd564090f2910d9615866e27dd7c7e32208094b0. Chain 2 (Bitcoin): anchored in block 958373 (2026-07-17T06:09:33Z), 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/TCAHT2307529.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37d1e3408b3b595886f19f76c3c28062166cf378434809f7b823b017b9fb79ba. Chain 2 (Bitcoin): anchored in block 958607 (2026-07-18T21:01:11Z), 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/TCAHX2459172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe28a5704d60f6f4faf9cb50ec1d60b9850c86ee22e85088c56d595be1544f724. Chain 2 (Bitcoin): anchored in block 958594 (2026-07-18T18:05:01Z), 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/FRERZ2400060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b8e100bd34de62d127caa644a60ea686e2516fcd4fabe2e5cf4e590febac4e1. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/FRERZ2400090.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4cb19380f040394610551b10fa558e3d21e338d703b405c44e90599ff35aa153. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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/FRERZ2500010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa623c38c9ab03779c4c1e19c443777b39f1882de3cc6b0d33c9566606275f011. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/FRERZ2500020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ed74e4beaa9529788c02cd1989d99b64aa29048def780fbc49b7c10392d36da. Chain 2 (Bitcoin): anchored in block 958091 (2026-07-15T03:17:03Z), 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/FRERZ2500040.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe28a5704d60f6f4faf9cb50ec1d60b9850c86ee22e85088c56d595be1544f724. Chain 2 (Bitcoin): anchored in block 958373 (2026-07-17T06:09:33Z), 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/FRERZ2400060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a856552b9f2f55040bdfa1c27bb3af49734d3e51968d1dc7d964c90e3382159. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/FRERZ2500060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0cc9250c864ccc5526c1af5f59edbe03d2c48b53bb140a8a918fd1984d5eb1b9. Chain 2 (Bitcoin): anchored in block 958153 (2026-07-15T12:03:04Z), 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/FRERZ2500080.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x41b216ac9b65d3fcca38d0aa5d07b670478dbda331b7d3dce236549f10c26766. Chain 2 (Bitcoin): anchored in block 958157 (2026-07-15T13:14:32Z), 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/FRERZ2500090.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1298f9556aad8c5e6a11e57795d6d9e5d3e2fb2bfcc5b3e42273a029c1d7d5e2. Chain 2 (Bitcoin): anchored in block 958362 (2026-07-17T04:32:48Z), 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/FRERZ2500100.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37d1e3408b3b595886f19f76c3c28062166cf378434809f7b823b017b9fb79ba. Chain 2 (Bitcoin): anchored in block 958176 (2026-07-15T17:14:36Z), 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/TCAHX2459172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb9d6574a1e9a86c1e8d59ddacaf5cc65a71930f06e9e60a99ccdd82b74873736. Chain 2 (Bitcoin): anchored in block 958263 (2026-07-16T08:19:47Z), 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/FRERZ2500120.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe6f922baccd0efaa730609e46cc03b42501e76914ab219894bd18dabcd7e34f5. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/FRERZ2500130.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xebef7a99f690f1a5682a91f300866ea3516b67d1f40148cfc81c25718a56e264. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/FRERZ2500140.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4cb19380f040394610551b10fa558e3d21e338d703b405c44e90599ff35aa153. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/FRERZ2500010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa623c38c9ab03779c4c1e19c443777b39f1882de3cc6b0d33c9566606275f011. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/FRERZ2500020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x946974ecac7a24618a02d3135fe8974c8344bc7d9f2e89b2853e1b0dbbc956df. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/FR9W12434738.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe39385ac919f7fcd6e5d3efc21797656688a93f3b6217e8e8b8cc72eeba7c6bd. Chain 2 (Bitcoin): anchored in block 958917 (2026-07-20T17:53:56Z), 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/FRERZ2500030.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ed74e4beaa9529788c02cd1989d99b64aa29048def780fbc49b7c10392d36da. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/FRERZ2500040.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe28a5704d60f6f4faf9cb50ec1d60b9850c86ee22e85088c56d595be1544f724. Chain 2 (Bitcoin): anchored in block 958830 (2026-07-20T05:30:12Z), 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/FRERZ2400060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x47f16e6ad442535ce4778e3fd138711e6dffa0493da8a7cac26a81950eedb15a. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/FRERZ2500050.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a856552b9f2f55040bdfa1c27bb3af49734d3e51968d1dc7d964c90e3382159. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/FRERZ2500060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7539ba1457e1e5898c824b4f4dc80ccd79fc36759d958a6e2a14e6716787cf3e. Chain 2 (Bitcoin): anchored in block 958796 (2026-07-20T00:01:46Z), 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/FRERZ2500070.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0cc9250c864ccc5526c1af5f59edbe03d2c48b53bb140a8a918fd1984d5eb1b9. Chain 2 (Bitcoin): anchored in block 959107 (2026-07-22T07:19:23Z), 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/FRERZ2500080.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37d1e3408b3b595886f19f76c3c28062166cf378434809f7b823b017b9fb79ba. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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/TCAHX2459172.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b8e100bd34de62d127caa644a60ea686e2516fcd4fabe2e5cf4e590febac4e1. Chain 2 (Bitcoin): anchored in block 956861 (2026-07-06T01:57:57Z), 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/FRERZ2400090.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7754d99932e62dfe321a8e6bd564090f2910d9615866e27dd7c7e32208094b0. Chain 2 (Bitcoin): anchored in block 958808 (2026-07-20T02:49:15Z), 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/TCAHT2307529.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb1b41a1844968b22bdb27414864d34ebc685357012a5dde0a9bb84c4dc79e38. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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/FRERZ2500390.