{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:QFPYXKUGCVS2I4ZVVX25UA2I3H","short_pith_number":"pith:QFPYXKUG","canonical_record":{"source":{"id":"1502.06577","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CR","submitted_at":"2015-02-23T20:12:54Z","cross_cats_sorted":["cs.CY"],"title_canon_sha256":"5a906798aa42a9956e64a974a0166f7df683b8dc0fa53c8d976a5af3cb272b82","abstract_canon_sha256":"5c2e6168db891ea0b920961e504ee143989318cc4151019d597cc6362e5894e0"},"schema_version":"1.0"},"canonical_sha256":"815f8baa861565a47335adf5da0348d9ee9f93a1bbdbc58631a30c6aadb79c98","source":{"kind":"arxiv","id":"1502.06577","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1502.06577","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"arxiv_version","alias_value":"1502.06577v1","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1502.06577","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"pith_short_12","alias_value":"QFPYXKUGCVS2","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_16","alias_value":"QFPYXKUGCVS2I4ZV","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_8","alias_value":"QFPYXKUG","created_at":"2026-05-18T12:29:37Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:QFPYXKUGCVS2I4ZVVX25UA2I3H","target":"record","payload":{"canonical_record":{"source":{"id":"1502.06577","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CR","submitted_at":"2015-02-23T20:12:54Z","cross_cats_sorted":["cs.CY"],"title_canon_sha256":"5a906798aa42a9956e64a974a0166f7df683b8dc0fa53c8d976a5af3cb272b82","abstract_canon_sha256":"5c2e6168db891ea0b920961e504ee143989318cc4151019d597cc6362e5894e0"},"schema_version":"1.0"},"canonical_sha256":"815f8baa861565a47335adf5da0348d9ee9f93a1bbdbc58631a30c6aadb79c98","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:26:32.253226Z","signature_b64":"w1llDbaDHZfd2yUqWFzWnQIyAGNSo9Vdgy3ARRvJ9YubHYPGAow81rJ/OsM6lTm/qpLANzQotPW8+fHoKoq6Ag==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"815f8baa861565a47335adf5da0348d9ee9f93a1bbdbc58631a30c6aadb79c98","last_reissued_at":"2026-05-18T02:26:32.252878Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:26:32.252878Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1502.06577","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":"2026-05-18T02:26:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"iP3S3pNvI/G4pB9ciOmpip2gq2T01EHEWAh3ptrO3GVjk+xcI3MAAr6uqIbj3UExtnSvozybVEG4hlHb/kaKAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T17:32:51.854955Z"},"content_sha256":"f2294408ff1468cd9a9e60c9d698c9da5523e7ba70660d5c20566ff611ccd53b","schema_version":"1.0","event_id":"sha256:f2294408ff1468cd9a9e60c9d698c9da5523e7ba70660d5c20566ff611ccd53b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:QFPYXKUGCVS2I4ZVVX25UA2I3H","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"An Empirical Study of Mobile Ad Targeting","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.CY"],"primary_cat":"cs.CR","authors_text":"Dan S. Wallach, Theodore Book","submitted_at":"2015-02-23T20:12:54Z","abstract_excerpt":"Advertising, long the financial mainstay of the web ecosystem, has become nearly ubiquitous in the world of mobile apps. While ad targeting on the web is fairly well understood, mobile ad targeting is much less studied. In this paper, we use empirical methods to collect a database of over 225,000 ads on 32 simulated devices hosting one of three distinct user profiles. We then analyze how the ads are targeted by correlating ads to potential targeting profiles using Bayes' rule and Pearson's chi squared test. This enables us to measure the prevalence of different forms of targeting. We find that"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.06577","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":"2026-05-18T02:26:32Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"t08FyG9Wfk9sjPW7JLV7VyRNMFtpblYegsK3WNoJqTXIMc93acHzDUyrHZeuYHGhvRu+JX7uiQuGqA7W7HpJCw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-07T17:32:51.855601Z"},"content_sha256":"9560c4f47c3cc05f7316efe3dbb147bc8a492edb3f0d7696801b05f79f47603c","schema_version":"1.0","event_id":"sha256:9560c4f47c3cc05f7316efe3dbb147bc8a492edb3f0d7696801b05f79f47603c"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/bundle.json","state_url":"https://pith.science/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/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":"2026-06-07T17:32:51Z","links":{"resolver":"https://pith.science/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H","bundle":"https://pith.science/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/bundle.json","state":"https://pith.science/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/state.json","well_known_bundle":"https://pith.science/.well-known/pith/QFPYXKUGCVS2I4ZVVX25UA2I3H/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:QFPYXKUGCVS2I4ZVVX25UA2I3H","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":"5c2e6168db891ea0b920961e504ee143989318cc4151019d597cc6362e5894e0","cross_cats_sorted":["cs.CY"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CR","submitted_at":"2015-02-23T20:12:54Z","title_canon_sha256":"5a906798aa42a9956e64a974a0166f7df683b8dc0fa53c8d976a5af3cb272b82"},"schema_version":"1.0","source":{"id":"1502.06577","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1502.06577","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"arxiv_version","alias_value":"1502.06577v1","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1502.06577","created_at":"2026-05-18T02:26:32Z"},{"alias_kind":"pith_short_12","alias_value":"QFPYXKUGCVS2","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_16","alias_value":"QFPYXKUGCVS2I4ZV","created_at":"2026-05-18T12:29:37Z"},{"alias_kind":"pith_short_8","alias_value":"QFPYXKUG","created_at":"2026-05-18T12:29:37Z"}],"graph_snapshots":[{"event_id":"sha256:9560c4f47c3cc05f7316efe3dbb147bc8a492edb3f0d7696801b05f79f47603c","target":"graph","created_at":"2026-05-18T02:26:32Z","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":"Advertising, long the financial mainstay of the web ecosystem, has become nearly ubiquitous in the world of mobile apps. While ad targeting on the web is fairly well understood, mobile ad targeting is much less studied. In this paper, we use empirical methods to collect a database of over 225,000 ads on 32 simulated devices hosting one of three distinct user profiles. We then analyze how the ads are targeted by correlating ads to potential targeting profiles using Bayes' rule and Pearson's chi squared test. This enables us to measure the prevalence of different forms of targeting. We find that","authors_text":"Dan S. Wallach, Theodore Book","cross_cats":["cs.CY"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CR","submitted_at":"2015-02-23T20:12:54Z","title":"An Empirical Study of Mobile Ad Targeting"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.06577","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:f2294408ff1468cd9a9e60c9d698c9da5523e7ba70660d5c20566ff611ccd53b","target":"record","created_at":"2026-05-18T02:26:32Z","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":"5c2e6168db891ea0b920961e504ee143989318cc4151019d597cc6362e5894e0","cross_cats_sorted":["cs.CY"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CR","submitted_at":"2015-02-23T20:12:54Z","title_canon_sha256":"5a906798aa42a9956e64a974a0166f7df683b8dc0fa53c8d976a5af3cb272b82"},"schema_version":"1.0","source":{"id":"1502.06577","kind":"arxiv","version":1}},"canonical_sha256":"815f8baa861565a47335adf5da0348d9ee9f93a1bbdbc58631a30c6aadb79c98","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"815f8baa861565a47335adf5da0348d9ee9f93a1bbdbc58631a30c6aadb79c98","first_computed_at":"2026-05-18T02:26:32.252878Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:26:32.252878Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"w1llDbaDHZfd2yUqWFzWnQIyAGNSo9Vdgy3ARRvJ9YubHYPGAow81rJ/OsM6lTm/qpLANzQotPW8+fHoKoq6Ag==","signature_status":"signed_v1","signed_at":"2026-05-18T02:26:32.253226Z","signed_message":"canonical_sha256_bytes"},"source_id":"1502.06577","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:f2294408ff1468cd9a9e60c9d698c9da5523e7ba70660d5c20566ff611ccd53b","sha256:9560c4f47c3cc05f7316efe3dbb147bc8a492edb3f0d7696801b05f79f47603c"],"state_sha256":"f14c6fedb00181098e6c3b813f865252b95c4499a2f64f20b4048be64ed3338b"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ySyMvpV4DIqABNZughNaU1Peq7L8wte+sYaBSyhhHYpZ8pIY1IYt+acHz+zSUq0YBgt8Vsck50tdMp7SYaJmDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-07T17:32:51.858960Z","bundle_sha256":"245f63e0b14e044d15b85919187f191b660d9396e9a808a4b242e11b30d85cc8"}}