{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:1999:F2JBQUTLWXA2DUB2CWW5D6U4UY","short_pith_number":"pith:F2JBQUTL","canonical_record":{"source":{"id":"quant-ph/9906074","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"quant-ph","submitted_at":"1999-06-21T07:25:38Z","cross_cats_sorted":[],"title_canon_sha256":"f1167b93bae24401643bd58d4f7ab44ccfb5e1443c884545afc24312d821c561","abstract_canon_sha256":"1914d486e96a8ef2ea2024c262d68ce277ca04ee971973a86d039d4779b63a0e"},"schema_version":"1.0"},"canonical_sha256":"2e9218526bb5c1a1d03a15add1fa9ca63e6c8dfe99f7571fc7ff734b525c882b","source":{"kind":"arxiv","id":"quant-ph/9906074","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"quant-ph/9906074","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"arxiv_version","alias_value":"quant-ph/9906074v1","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.quant-ph/9906074","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"pith_short_12","alias_value":"F2JBQUTLWXA2","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"F2JBQUTLWXA2DUB2","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"F2JBQUTL","created_at":"2026-05-18T12:25:49Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:1999:F2JBQUTLWXA2DUB2CWW5D6U4UY","target":"record","payload":{"canonical_record":{"source":{"id":"quant-ph/9906074","kind":"arxiv","version":1},"metadata":{"license":"","primary_cat":"quant-ph","submitted_at":"1999-06-21T07:25:38Z","cross_cats_sorted":[],"title_canon_sha256":"f1167b93bae24401643bd58d4f7ab44ccfb5e1443c884545afc24312d821c561","abstract_canon_sha256":"1914d486e96a8ef2ea2024c262d68ce277ca04ee971973a86d039d4779b63a0e"},"schema_version":"1.0"},"canonical_sha256":"2e9218526bb5c1a1d03a15add1fa9ca63e6c8dfe99f7571fc7ff734b525c882b","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:16:51.739901Z","signature_b64":"I03GuvZsO5dwtwoMXRSWENnCmkp4w8XSWXMjWe3nHdS7qpbNKP3VjaMbV6DaUVTDA3JCqN0QWVz8v65Qu1g9BA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2e9218526bb5c1a1d03a15add1fa9ca63e6c8dfe99f7571fc7ff734b525c882b","last_reissued_at":"2026-05-18T02:16:51.739106Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:16:51.739106Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"quant-ph/9906074","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":"2026-05-18T02:16:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"gkepT4UHC+EV5nNj5hnX14cXqM/8qLNG8pNICjZO9IJjKzPGvJ56EKG7Ttc/YQDdMItenISXJdFi05vxlvT+CQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T21:08:36.061757Z"},"content_sha256":"bcd2955075e3fd0b051886b92e48125fefb8fef2e495606b6a5f65aeee812371","schema_version":"1.0","event_id":"sha256:bcd2955075e3fd0b051886b92e48125fefb8fef2e495606b6a5f65aeee812371"},{"event_type":"graph_snapshot","subject_pith_number":"pith:1999:F2JBQUTLWXA2DUB2CWW5D6U4UY","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Quantum cryptography via parametric downconversion","license":"","headline":"","cross_cats":[],"primary_cat":"quant-ph","authors_text":"Barry C. Sanders, Gilles Brassard, Tal Mor","submitted_at":"1999-06-21T07:25:38Z","abstract_excerpt":"The use of quantum bits (qubits) in cryptography holds the promise of secure cryptographic quantum key distribution schemes. It is based usually on single-photon polarization states. Unfortunately, the implemented ``qubits'' in the usual weak pulse experiments are not true two-level systems, and quantum key distribution based on these imperfect qubits is totally insecure in the presence of high (realistic) loss rate. In this work, we investigate another potential implementation: qubits generated using a process of parametric downconversion. We find that, to first (two-photon) and second (four-"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"quant-ph/9906074","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":"2026-05-18T02:16:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"b3WUQvuZlxlUn8TgSDJMOqVlR5AwppjUOiq1MbL8UfZA8U7l2LSMp3I/gS/z5giNa1FeuMvDEoxQUXluXLH3AA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T21:08:36.062446Z"},"content_sha256":"06f5e740af31141b44c5006981bf877bee5008822f66446aa465392a95529380","schema_version":"1.0","event_id":"sha256:06f5e740af31141b44c5006981bf877bee5008822f66446aa465392a95529380"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/bundle.json","state_url":"https://pith.science/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/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":"2026-05-28T21:08:36Z","links":{"resolver":"https://pith.science/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY","bundle":"https://pith.science/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/bundle.json","state":"https://pith.science/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/state.json","well_known_bundle":"https://pith.science/.well-known/pith/F2JBQUTLWXA2DUB2CWW5D6U4UY/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1999:F2JBQUTLWXA2DUB2CWW5D6U4UY","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":"1914d486e96a8ef2ea2024c262d68ce277ca04ee971973a86d039d4779b63a0e","cross_cats_sorted":[],"license":"","primary_cat":"quant-ph","submitted_at":"1999-06-21T07:25:38Z","title_canon_sha256":"f1167b93bae24401643bd58d4f7ab44ccfb5e1443c884545afc24312d821c561"},"schema_version":"1.0","source":{"id":"quant-ph/9906074","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"quant-ph/9906074","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"arxiv_version","alias_value":"quant-ph/9906074v1","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.quant-ph/9906074","created_at":"2026-05-18T02:16:51Z"},{"alias_kind":"pith_short_12","alias_value":"F2JBQUTLWXA2","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_16","alias_value":"F2JBQUTLWXA2DUB2","created_at":"2026-05-18T12:25:49Z"},{"alias_kind":"pith_short_8","alias_value":"F2JBQUTL","created_at":"2026-05-18T12:25:49Z"}],"graph_snapshots":[{"event_id":"sha256:06f5e740af31141b44c5006981bf877bee5008822f66446aa465392a95529380","target":"graph","created_at":"2026-05-18T02:16:51Z","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":"The use of quantum bits (qubits) in cryptography holds the promise of secure cryptographic quantum key distribution schemes. It is based usually on single-photon polarization states. Unfortunately, the implemented ``qubits'' in the usual weak pulse experiments are not true two-level systems, and quantum key distribution based on these imperfect qubits is totally insecure in the presence of high (realistic) loss rate. In this work, we investigate another potential implementation: qubits generated using a process of parametric downconversion. We find that, to first (two-photon) and second (four-","authors_text":"Barry C. Sanders, Gilles Brassard, Tal Mor","cross_cats":[],"headline":"","license":"","primary_cat":"quant-ph","submitted_at":"1999-06-21T07:25:38Z","title":"Quantum cryptography via parametric downconversion"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"quant-ph/9906074","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:bcd2955075e3fd0b051886b92e48125fefb8fef2e495606b6a5f65aeee812371","target":"record","created_at":"2026-05-18T02:16:51Z","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":"1914d486e96a8ef2ea2024c262d68ce277ca04ee971973a86d039d4779b63a0e","cross_cats_sorted":[],"license":"","primary_cat":"quant-ph","submitted_at":"1999-06-21T07:25:38Z","title_canon_sha256":"f1167b93bae24401643bd58d4f7ab44ccfb5e1443c884545afc24312d821c561"},"schema_version":"1.0","source":{"id":"quant-ph/9906074","kind":"arxiv","version":1}},"canonical_sha256":"2e9218526bb5c1a1d03a15add1fa9ca63e6c8dfe99f7571fc7ff734b525c882b","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2e9218526bb5c1a1d03a15add1fa9ca63e6c8dfe99f7571fc7ff734b525c882b","first_computed_at":"2026-05-18T02:16:51.739106Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:16:51.739106Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"I03GuvZsO5dwtwoMXRSWENnCmkp4w8XSWXMjWe3nHdS7qpbNKP3VjaMbV6DaUVTDA3JCqN0QWVz8v65Qu1g9BA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:16:51.739901Z","signed_message":"canonical_sha256_bytes"},"source_id":"quant-ph/9906074","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:bcd2955075e3fd0b051886b92e48125fefb8fef2e495606b6a5f65aeee812371","sha256:06f5e740af31141b44c5006981bf877bee5008822f66446aa465392a95529380"],"state_sha256":"4fa300c053f4c0f38f3de64632fe76268d4749b0ed96793eef0fc7b9d1cc4e1c"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rc9AwT613AWwiOknMz7vprhI2EdU6hCAybcF6FWcY34M0bEK4h7WLm43I93TQanRXm0uVPcsUzj37wy3JlaCBA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T21:08:36.065995Z","bundle_sha256":"db44641a62f0c9c9092056091e34220f4e9bc4965729a7cf51a9a811afda75d5"}}