Alexandra Lange is an American architecture and design critic and author based in New York. She won the 2025 Pulitzer Prize for Criticism, as a contributing writer for Bloomberg Citylab. The author of
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 0xaa8dd86e6790ac4cfd80b9d3268f5b1be3b7df3936045a5a1b9af9fa7a867390. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8b6199dc-665f-48cb-bf5a-c017907979ea.json and https://artists.proofprofile.net/proofs/artist/8b6199dc-665f-48cb-bf5a-c017907979ea.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 0xe6d918c57c1d09003e1516499e433292f569a53638953e4f1d4fb60a7e8657df. 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/DEHC20981771.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x068d1d361a91fd47e27840b2a4f793b59f116eeb408d4bebc6364a0f7cde7655. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/DEHC20981772.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x684c1580f1117666fd0bc66292dcd7511bb8155dd7c09557011d7b5189f91dbb. 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/DEHC20981773.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x74f39ba1d0d412d0bb536ac09e5314435481cc65d98c42cda91f719863bf3bcd. 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/DEHC20981776.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf04aba9a2217415c7cbd2e5c3c3882d3fa191a4d175bab728e22ad3f0067f198. 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/DEHC20981777.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe1717821c2321bf86df1688951311ca0a835b329372a8aaaa38a9c6bc93e932e. 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/DEHC20981779.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7dbd47e1326f627db3f2e922ddf1f14ebcdb639802022d50056f3cee1b018b1a. 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/DEHC20981781.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x826259702132c34954252f95a519060026f0c60252efa83af14110fecabe1de5. 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/DEHC20981784.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f4f3f737e2a2350a9ff7581691d3375e134a95fd61b09b71ed405159517e0ab. Chain 2 (Bitcoin): anchored in block 957819 (2026-07-13T07:53:33Z), 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/DEHC20981785.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1af352f668f1d0f0c9e51493d053cca6136a3880a8cd104bd445141c60b74b5d. 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/DEHC20981786.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc73f727e60c10fa2a7d28f8d98ae72be2f18a4db4308ddd51567b1d44455aaf3. 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/DEHC20981775.
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 0x9f40f348944a057696e08988cb01247a748f3e7970f4e6f57c7e3996a65900fd. Chain 2 (Bitcoin): anchored in block 959163 (2026-07-22T20:53:15Z), 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/DEHC20981778.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc0653bc5a82df993002684f70f28139a1003be80b0aedb3f0f82a051c5cea206. Chain 2 (Bitcoin): anchored in block 959147 (2026-07-22T15:43:44Z), 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/DEHC20981787.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9255c7d845ed25409bee93e156c504b3ef4e3575968b5a3456bfe1f36491a384. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/DEHC20981774.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb1422afb57e2193ec36029a7ca05443074fd3ef62d361a9743da17ebbebc0cd. Chain 2 (Bitcoin): anchored in block 960099 (2026-07-29T11:30:20Z), 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/DEHC20981780.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xacf658f143c98541268d5c07682708850a4f95a97a7ef92ad91767bfd9c87c0b. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/DEHC20981782.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6141a3b9a28d0a1e459d92719ada868fba39917f0fc80c1a586387e2b8a4e3ac. 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/DEHC20981783.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5043bdda999e1a44a5212d92ad2e422e09f041e30f4f794841efca2cdde64ad0. 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/DEHC20981788.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb450487cff4522a7db21153136e0d588302aa93fbaacf393211f06bd54f00ce. Chain 2 (Bitcoin): anchored in block 960185 (2026-07-30T01:32:48Z), 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/DEHC20981789.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x076cd263101891e0c870edf4d874ff6ac07bf61ea660add78c470c44ed78bb14. Chain 2 (Bitcoin): anchored in block 960099 (2026-07-29T11:30:20Z), 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/DEHC20981790.