Sylwia Karolina Grzeszczak (born 7 April 1989) is a Polish singer-songwriter, compositor and pianist. She debuted in 2008 with the album Ona i On, which she recorded with . Afterwards, she released
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 0x57f4ecfc6a0c434ca72c0ae7714c36c1176d361f9990e3d2d634312e9440d575. 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/4d39a6d8-dc34-444d-a6f8-0d1060e0f2e1.json and https://artists.proofprofile.net/proofs/artist/4d39a6d8-dc34-444d-a6f8-0d1060e0f2e1.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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x735c017e226bf7280feb1ace6a0411521220cdea0e035ea9ec492d8b81250ad0. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/PLC060900396.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd2e8e3ff0f8948dd6614f29b8bd1ac42dcf217744124424d29d84ebade2691d. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/PLC060900397.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd22bdd4643b29b4e8fc365b60ee8024410e9bc8379d8d07d6e2685dbcf93df1a. 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/PLC060900398.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c0db0aac5662c6ba405ebb2ff18998825b6f3c35e87fd51c53b7d16c03c7431. 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/PLC060900399.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92bd3ceda293a2947743a112c085520fe3a3497563fbf9d509c3ec90428dea20. 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/PLC060900400.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa0a22a7f258742bbe4b30029c9d55e67aebdea9acc23872626eaf393b78b2be8. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/PLC060900401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e5b486a843396545de35447d7938ff7f2e663cb5b436f7797a8bc2e5fb90451. 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/PLC060900402.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa33e84414a41c553cd2582993723a4dcec981959157eab35fa7809876ce62624. 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/PLC060900403.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc740012c032419c670328daa1ddfd5725e786d125bab72d9d005b6b0af40e17e. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/PLC060900404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d5d3b44437f700a564b8d97d785ac7cedf22edad77cd88fefef9316586629c9. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLC060900405.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x36ea2863b4fa5b9f20f53f5a1aa8b5ecf6d677d3084f80fa15449e6a87f6a1ff. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/PLC060900406.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc85321234d8e20585b95136348ca7fe08843b7b0e8bf810874df0840909fe5dd. 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/PLC060900407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c19439f17a502a90ab9a794fd4318f6b02a2a27d865e8ecd6d21235bb1168f1. 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/PLC060900408.
Kiedy tylko spojrzę (feat. Sound'n'Grace)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa0da6ed3befe39254cae17ca3f4de3d2ec001dcf953c4add30fa91e37450a2e. 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/PLC271600030.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x80d9f1c9b81dd69db6c0779d7dbbb7bcc6785485eeaff255f8424676867b8de6. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/PLC271600033.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf3351e0e47533631c432f15b6afd43077fc14792b64f2772d9edfa9b784154bd. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLC271600013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd0df2cbe35868d9488174ca0b97b5119f603a1c9d0537b7debdcae658b41f1d6. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/PLC271600024.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0becfe90e7262a8c37e52142a00df9e6918715916b049084b4d1c7c808c24f54. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLC271600025.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4e5e407a2ce92fd385bd44644b71ca756f66be3204f9b37f3bc9c9ad835b566. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLC271600026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29e85f193c22efa2d22221b34065a5acaced4b60d217612b2f2c1bd9f4d9fa0d. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/PLC271600027.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xea8e9d1ed6233e164bcdfcd52f35ea55e4754419af62aa18d2b124826c39f72b. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/PLC271600028.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1f453f9c884eb527654f087e7c11f804eed733058f579b4b24cd98aa090e52d4. 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/PLC271600029.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa0da6ed3befe39254cae17ca3f4de3d2ec001dcf953c4add30fa91e37450a2e. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLC271600030.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb982c45c6c74c706bcccd154db5a1652b246d552452c5fac7cbbad3edc2b25b6. 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/PLC271600031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fbda875cc03e9fc835bb02465c6ee14c39a05b6e5b2ef330ea44cb561df63fc. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/PLA551800375.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb41139a31703e2d6cb604a042bafa3d1081bbb37da13f296426ac21ca5a6a416. 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/PLA552400384.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb41139a31703e2d6cb604a042bafa3d1081bbb37da13f296426ac21ca5a6a416. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/PLA552400384.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb41139a31703e2d6cb604a042bafa3d1081bbb37da13f296426ac21ca5a6a416. 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/PLA552400384.