{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2004:EAJVAQDPVA7P5RLBHG2O6XU3VS","short_pith_number":"pith:EAJVAQDP","canonical_record":{"source":{"id":"quant-ph/0411092","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"quant-ph","submitted_at":"2004-11-12T17:36:42Z","cross_cats_sorted":[],"title_canon_sha256":"40f4162eded57aee62f46ef3b985086d76e3ed3f64d85dc631023a564a7a3c42","abstract_canon_sha256":"8845a42dd2988f875f3b00ffce715bb78dfbcedd7ec84e129425d458d5d4f7be"},"schema_version":"1.0"},"canonical_sha256":"201350406fa83efec56139b4ef5e9bac85b63081eaf034b38bf2999d31e98482","source":{"kind":"arxiv","id":"quant-ph/0411092","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"quant-ph/0411092","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"arxiv_version","alias_value":"quant-ph/0411092v1","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.quant-ph/0411092","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"pith_short_12","alias_value":"EAJVAQDPVA7P","created_at":"2026-05-18T12:25:52Z"},{"alias_kind":"pith_short_16","alias_value":"EAJVAQDPVA7P5RLB","created_at":"2026-05-18T12:25:52Z"},{"alias_kind":"pith_short_8","alias_value":"EAJVAQDP","created_at":"2026-05-18T12:25:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2004:EAJVAQDPVA7P5RLBHG2O6XU3VS","target":"record","payload":{"canonical_record":{"source":{"id":"quant-ph/0411092","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"quant-ph","submitted_at":"2004-11-12T17:36:42Z","cross_cats_sorted":[],"title_canon_sha256":"40f4162eded57aee62f46ef3b985086d76e3ed3f64d85dc631023a564a7a3c42","abstract_canon_sha256":"8845a42dd2988f875f3b00ffce715bb78dfbcedd7ec84e129425d458d5d4f7be"},"schema_version":"1.0"},"canonical_sha256":"201350406fa83efec56139b4ef5e9bac85b63081eaf034b38bf2999d31e98482","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:08:45.742831Z","signature_b64":"mUuIub+2shJrbQm1D9/hJ7o6TE9QVRGJOEFkZIr5/BCsN/EPeqGlSHS+bd4g0eRuK6sRRmOY0gUyKL41RR2aBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"201350406fa83efec56139b4ef5e9bac85b63081eaf034b38bf2999d31e98482","last_reissued_at":"2026-05-18T01:08:45.742466Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:08:45.742466Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"quant-ph/0411092","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:08:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ACBNZeQvxD+HxsQoXvHSedKEQQvwSdPsP3EuAsRfr765a2GudBJCwxTCX9QMc70AVAQdgOphoAZC2rBMDwxODg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T10:43:02.856668Z"},"content_sha256":"c8e75e6ebf03571044f7fb8fe2e046b340b96cf32d271b740c190ff66e2a1e1b","schema_version":"1.0","event_id":"sha256:c8e75e6ebf03571044f7fb8fe2e046b340b96cf32d271b740c190ff66e2a1e1b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2004:EAJVAQDPVA7P5RLBHG2O6XU3VS","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Secrecy content of two-qubit states","license":"","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"A. Ac\\'in, E. Bagan, J. Bae, Ll. Masanes, M. Baig, R. Mu\\~noz-Tapia","submitted_at":"2004-11-12T17:36:42Z","abstract_excerpt":"We analyze the set of two-qubit states from which a secret key can be extracted by single-copy measurements plus classical processing of the outcomes. We introduce a key distillation protocol and give the corresponding necessary and sufficient condition for positive key extraction. Our results imply that the critical error rate derived by Chau, Phys. Rev. A {\\bf 66}, 060302 (2002), for a secure key distribution using the six-state scheme is tight. Remarkably, an optimal eavesdropping attack against this protocol does not require any coherent quantum operation."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"quant-ph/0411092","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:08:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"7niye4TBgSDnJPYkXF9zk+lry0Zli588pogja5wSvOWNm0El6o0+qwZwwOfpyJs6Ji0LIKuRmQ3awgcLqMr+BQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T10:43:02.857375Z"},"content_sha256":"2579f47a78fb1a09893e610da0d8b355fd2ab093231a07fb4a9337f2c54e8767","schema_version":"1.0","event_id":"sha256:2579f47a78fb1a09893e610da0d8b355fd2ab093231a07fb4a9337f2c54e8767"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/bundle.json","state_url":"https://pith.science/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-27T10:43:02Z","links":{"resolver":"https://pith.science/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS","bundle":"https://pith.science/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/bundle.json","state":"https://pith.science/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/state.json","well_known_bundle":"https://pith.science/.well-known/pith/EAJVAQDPVA7P5RLBHG2O6XU3VS/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2004:EAJVAQDPVA7P5RLBHG2O6XU3VS","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"8845a42dd2988f875f3b00ffce715bb78dfbcedd7ec84e129425d458d5d4f7be","cross_cats_sorted":[],"license":"","primary_cat":"quant-ph","submitted_at":"2004-11-12T17:36:42Z","title_canon_sha256":"40f4162eded57aee62f46ef3b985086d76e3ed3f64d85dc631023a564a7a3c42"},"schema_version":"1.0","source":{"id":"quant-ph/0411092","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"quant-ph/0411092","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"arxiv_version","alias_value":"quant-ph/0411092v1","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.quant-ph/0411092","created_at":"2026-05-18T01:08:45Z"},{"alias_kind":"pith_short_12","alias_value":"EAJVAQDPVA7P","created_at":"2026-05-18T12:25:52Z"},{"alias_kind":"pith_short_16","alias_value":"EAJVAQDPVA7P5RLB","created_at":"2026-05-18T12:25:52Z"},{"alias_kind":"pith_short_8","alias_value":"EAJVAQDP","created_at":"2026-05-18T12:25:52Z"}],"graph_snapshots":[{"event_id":"sha256:2579f47a78fb1a09893e610da0d8b355fd2ab093231a07fb4a9337f2c54e8767","target":"graph","created_at":"2026-05-18T01:08:45Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"We analyze the set of two-qubit states from which a secret key can be extracted by single-copy measurements plus classical processing of the outcomes. We introduce a key distillation protocol and give the corresponding necessary and sufficient condition for positive key extraction. Our results imply that the critical error rate derived by Chau, Phys. Rev. A {\\bf 66}, 060302 (2002), for a secure key distribution using the six-state scheme is tight. Remarkably, an optimal eavesdropping attack against this protocol does not require any coherent quantum operation.","authors_text":"A. Ac\\'in, E. Bagan, J. Bae, Ll. Masanes, M. Baig, R. Mu\\~noz-Tapia","cross_cats":[],"headline":"","license":"","primary_cat":"quant-ph","submitted_at":"2004-11-12T17:36:42Z","title":"Secrecy content of two-qubit states"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"quant-ph/0411092","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:c8e75e6ebf03571044f7fb8fe2e046b340b96cf32d271b740c190ff66e2a1e1b","target":"record","created_at":"2026-05-18T01:08:45Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"8845a42dd2988f875f3b00ffce715bb78dfbcedd7ec84e129425d458d5d4f7be","cross_cats_sorted":[],"license":"","primary_cat":"quant-ph","submitted_at":"2004-11-12T17:36:42Z","title_canon_sha256":"40f4162eded57aee62f46ef3b985086d76e3ed3f64d85dc631023a564a7a3c42"},"schema_version":"1.0","source":{"id":"quant-ph/0411092","kind":"arxiv","version":1}},"canonical_sha256":"201350406fa83efec56139b4ef5e9bac85b63081eaf034b38bf2999d31e98482","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"201350406fa83efec56139b4ef5e9bac85b63081eaf034b38bf2999d31e98482","first_computed_at":"2026-05-18T01:08:45.742466Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:08:45.742466Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"mUuIub+2shJrbQm1D9/hJ7o6TE9QVRGJOEFkZIr5/BCsN/EPeqGlSHS+bd4g0eRuK6sRRmOY0gUyKL41RR2aBg==","signature_status":"signed_v1","signed_at":"2026-05-18T01:08:45.742831Z","signed_message":"canonical_sha256_bytes"},"source_id":"quant-ph/0411092","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c8e75e6ebf03571044f7fb8fe2e046b340b96cf32d271b740c190ff66e2a1e1b","sha256:2579f47a78fb1a09893e610da0d8b355fd2ab093231a07fb4a9337f2c54e8767"],"state_sha256":"64f89652443e58cd4a57628474cfadf2f5ea9c2ab26e9790adc36341377aa5ff"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uT2es+LloSlKgq7YhCmPKj9iuePfrHk5PvsF2vGba8Mkb8NTqmYfopVb7ZOQd2Lrlv4y0blOgchEpTvNwrvUBg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T10:43:02.861103Z","bundle_sha256":"8f71d900d12a2672afd89c24923413743e2f70795797c7571e90790689dca970"}}