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 0xfd831db22187e4cc23ad72e41e0561a5443be12d9eb180d9af625e353fc707aa. 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/ca66c025-94b3-45fe-a202-91cf62b00a66.json and https://artists.proofprofile.net/proofs/artist/ca66c025-94b3-45fe-a202-91cf62b00a66.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 0xab8493a6f4219b2de149c288d6f6871db967f4238a3279c63c7e66b4758eafaa. 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/TCAFR2187067.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x82a9073826552ff9e9afc0ed71bc4c3b8c03222e7e3e21f0313ba1133fc40929. 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/TCAFR2187075.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x422e7af5389bee31cd57c32ffcca91b294f70bfeddadae3046f4d3d128e5e9f7. Chain 2 (Bitcoin): anchored in block 958130 (2026-07-15T08:37:45Z), 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/TCAFM2111514.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x679acabf4c6b3615bd89004de45e4bb122ee1285174d471fcf1c3e159bdbb5da. 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/TCAFM2111687.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x585ca5f0b6a75bf97157b13569ac033c6e13bf272391c801cc7cc114d7c46fdd. Chain 2 (Bitcoin): anchored in block 957763 (2026-07-12T22:01:25Z), 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/USDY41955450.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0ef2ef642ba348a297adbb9aa5650a5b347d88974e022e5debcfa615e1d974c3. 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/USDY41955451.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8d8f6d2861aab66d0d65f3cea882317a722baa847dd3af0e54e422cd4a5b7bbe. Chain 2 (Bitcoin): anchored in block 958931 (2026-07-20T21:15:01Z), 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/USHM91964822.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd206150b02342cef35e4024a65e88df1a0bc9c1f9a822969d494aa02500eedcd. Chain 2 (Bitcoin): anchored in block 958959 (2026-07-21T03:51:22Z), 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/USCGJ2157280.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4332b5d6a468548d080cc480045706f79b43e03043ff6db7d139a18dfc29af53. Chain 2 (Bitcoin): anchored in block 958104 (2026-07-15T05:34:05Z), 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/USCGJ2157356.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x059d384af96dae19efe21b4d2e24fec9b8677ff4cffd0e45137b906885ec6b27. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/TCAFT2116569.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1661ff5e44bb5e4569cd59a41e0b92365a6c8081e0f6ebde8eeb20f5d976070e. 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/TCAFT2118670.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4c2c6c825264d2818694ce87c2d6fbafacb8becc95e61ff24da31b9347eaa0d4. Chain 2 (Bitcoin): anchored in block 958959 (2026-07-21T03:51:22Z), 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/US3DF2239786.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d1b63f8abc3de5e02025a273fcb34140abd2f64f91b6468d199016a3fd29713. Chain 2 (Bitcoin): anchored in block 958180 (2026-07-15T17:59:52Z), 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/TCAGY2355044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa392b4d61aaeeb27baba3fb700cf7676c68ca88e4ade0089d885d0acf99469e5. Chain 2 (Bitcoin): anchored in block 958134 (2026-07-15T09:14:08Z), 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/TCAGY2355047.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5fbb6231919506bde69024e6263f3bd901638092221ca22c20994962f54575c. Chain 2 (Bitcoin): anchored in block 958455 (2026-07-17T21:28:36Z), 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/TCAHD2322844.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0707a68b491d09f4de5e6df79ade3b0fb0801fa625f9d306b533ec599534fc78. Chain 2 (Bitcoin): anchored in block 959069 (2026-07-21T22:32:59Z), 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/USCGH2494503.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8a9b4aae4a50e43f55237a06c4634dbed2826f18feb00844762a4ab5c8fd957a. Chain 2 (Bitcoin): anchored in block 957872 (2026-07-13T15:39:45Z), 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/MXA3V2421357.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb614c61c0874682cff8c061c5ab1a1ad289b7baf9a95755eb085b3db1c31e477. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T19:17:28Z), 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/MXA3V2421358.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xae061d3e1bf33424ae3dee37a32f11c29872a51072d773620c677a6842c3ec62. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/MXA3V2421360.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf2be4a3d69b3c3e99ff2f95349fda74771ba8a3c325a90ce08ae0a7cd2de3266. 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/MXA3V2421361.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6e60f64e6a01ed74105c3a84e5d975262cbcf508d6068c6ae8a959a9de6cb192. Chain 2 (Bitcoin): anchored in block 958126 (2026-07-15T08:17:14Z), 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/MXA3V2421363.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c3a8efc41bf7d64364409e54bc207c8d50311c3df28211e9ef4b029d1403d34. Chain 2 (Bitcoin): anchored in block 959008 (2026-07-21T13:14:05Z), 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/MXA3V2421367.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85d20d11d2b11735ca89975c109e60438e88cef9e3e7453000cc994d5363ec8d. Chain 2 (Bitcoin): anchored in block 958706 (2026-07-19T08:50:34Z), 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/MXA3V2421369.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94a1b2437716341fa2048f3417218e79c2c33ab2911c4239c8a46f43e3ef1045. 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/TCAJJ2538834.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5392f4d5133c865027d2ae72948fbe0bb93781ea2ed227a36d71683be3d4420d. Chain 2 (Bitcoin): anchored in block 957872 (2026-07-13T15:39:45Z), 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/MXA3V2427746.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3f814880506c0d46c47ae6100489fa2a45c9cecc7b7eff080210541a092701ff. 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/MXA3V2427747.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdbc6549dd4c94f536e194e668b3638cc6f03ce68b9f8d23043a3ec5cc22dc6a4. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/MXA3V2427749.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x775c35488f630df02dc59f61f996f5764b4149f214e796ea6fcfd4c179c31d90. 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/MXA3V2427750.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94e5493d803312f090c8e26466570bec58f80b7409ea08f79900a7ac9445b274. Chain 2 (Bitcoin): anchored in block 958211 (2026-07-15T23:24:33Z), 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/MXA3V2427751.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9414cca5fc4bb41387d315a5ba89a4ce7728c9a3134f2e3b081f46c1fbc2ed3e. 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/MXA3V2427752.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0c9970e2b1ac63b590ac8c3ce1c03ee47de194102fd7cabc869b4959626d263. Chain 2 (Bitcoin): anchored in block 958506 (2026-07-18T06:14:51Z), 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/MXA3V2427754.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c42c97524046837964e7f30f8126611305cadd35cb5c89b629873e7ee4f7516. Chain 2 (Bitcoin): anchored in block 958276 (2026-07-16T10:20:17Z), 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/MXA3V2427755.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3dac249f0ec6049479e88a50684f7f84e708ee8e955ed8b1e77745e2878021b6. Chain 2 (Bitcoin): anchored in block 956711 (2026-07-04T22:48:52Z), 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/MXA3V2427756.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4c0a0874bd4f1955984eb20f45c340d6dd1dbe0c80e80701416352f6d6b5a57f. 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/MXA3V2427758.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x79217a36b8d2dd4cd8137b733b3c2ff54e1246815a2d1324ae66fa1f1bc4531c. Chain 2 (Bitcoin): anchored in block 958316 (2026-07-16T19:42:29Z), 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/MXA3V2427759.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4606010cba9f28738ae02d2c1ab3508197ba72b3407abbd77b07cf75e42afc4b. 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/QT65X2546093.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xade9776282bd666bea6f673cb56191dd10a6d3c18255704d001b33da271458ab. Chain 2 (Bitcoin): anchored in block 957785 (2026-07-13T01:55:31Z), 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/QT65X2546414.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68e6c5e8592d0473d439ab55323b538afbd0eeabc953787c8d2ad99e34ef3924. 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/QT65X2548500.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc390594251323c29b9fe684ec5cdec3f24fd1c21797dce84bbd46ae640e0b55b. Chain 2 (Bitcoin): anchored in block 959155 (2026-07-22T16:43:41Z), 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/QT65X2548776.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd8383a73baaec8f517a687ec43995966fb74bee4f49381096f360a64ddea5467. Chain 2 (Bitcoin): anchored in block 958660 (2026-07-19T04:21:53Z), 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/QT65X2548963.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb17e32fba128d64026cc5f8837eefd31adb61e57368826322db578fb26247fb4. Chain 2 (Bitcoin): anchored in block 958110 (2026-07-15T06:57:12Z), 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/QT65X2548985.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa035963196632f0d58da05bce2a2583c02ad093a9d85bfc2e7b54d81d5141919. 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/USJTQ1311513.