{
  "schemaVersion": "benchmark-manifest-v1",
  "generatedAt": "2026-08-03T16:00:00+08:00",
  "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
  "c2patoolVersion": "c2patool 0.26.67",
  "frequencyThreshold": 0.7418555425813717,
  "caseCount": 16,
  "reviewedAt": "2026-08-24T12:00:00+08:00",
  "reviewMethod": "Automated evidence cross-check plus maintainer inspection of each input, report, and review record",
  "humanSignoff": {
    "complete": true,
    "pendingCases": [],
    "reason": "Img2det Project maintainer approved all 16 cases after checklist review."
  },
  "cases": [
    {
      "id": "camera-01",
      "category": "Camera original",
      "title": "Camera metadata baseline",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/camera-01.jpg",
      "inputUrl": "/benchmark/inputs/camera-01.jpg",
      "inputSha256": "2ac758e9ea4a07a57539066016b6f3bde2b49e114595cb1b175dd504c5e70b04",
      "reportFile": "backend/benchmarks/reports/camera-01.report.json",
      "reportUrl": "/benchmark/reports/camera-01.report.json",
      "reportSha256": "7a0b4cc43e83371beca302270e86b51985e3a10aabd2faa4ab892cb9e20ee327",
      "reviewFile": "backend/benchmarks/reviews/camera-01.review.json",
      "reviewUrl": "/benchmark/reviews/camera-01.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Deterministic project-owned RGB fixture saved once as JPEG quality 92 with synthetic test-camera EXIF.",
      "expectedEvidence": "Camera identity EXIF is present",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "camera-02",
      "category": "Camera original",
      "title": "Camera metadata removed",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/camera-02.jpg",
      "inputUrl": "/benchmark/inputs/camera-02.jpg",
      "inputSha256": "317c74b99452456a53cf9fb16ae7542defe4c2b55dead74cd0d2eee48553fbcf",
      "reportFile": "backend/benchmarks/reports/camera-02.report.json",
      "reportUrl": "/benchmark/reports/camera-02.report.json",
      "reportSha256": "bbf2dab92d8872c5871e6101f3d2ccae1d239d01b83ea88cdfd3b4fd19ba49f7",
      "reviewFile": "backend/benchmarks/reviews/camera-02.review.json",
      "reviewUrl": "/benchmark/reviews/camera-02.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded camera-01 pixels and saved as JPEG quality 92 without EXIF.",
      "expectedEvidence": "Camera identity EXIF is absent",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "camera-03",
      "category": "Camera original",
      "title": "Camera image recompressed once",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/camera-03.jpg",
      "inputUrl": "/benchmark/inputs/camera-03.jpg",
      "inputSha256": "3c22bbb92e0f3476eb5dff1361a7d749310521e6fcfc6b0322f7c2dbf26bc7a7",
      "reportFile": "backend/benchmarks/reports/camera-03.report.json",
      "reportUrl": "/benchmark/reports/camera-03.report.json",
      "reportSha256": "7dce0d5801b7d393d6a0b8fa1aa8de36d3280449b8373bc1f25f7602765a30c3",
      "reviewFile": "backend/benchmarks/reviews/camera-03.review.json",
      "reviewUrl": "/benchmark/reviews/camera-03.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded camera-01 and recompressed once as JPEG quality 72 while retaining its test EXIF.",
      "expectedEvidence": "Retained EXIF and JPEG quantization are detected",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "camera-04",
      "category": "Camera original",
      "title": "Camera image converted to WebP",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/camera-04.webp",
      "inputUrl": "/benchmark/inputs/camera-04.webp",
      "inputSha256": "728f2ec3f7f596cbdbe73fbdab04f19e0f57b4e372fb6f495e477bd73e0e8f3f",
      "reportFile": "backend/benchmarks/reports/camera-04.report.json",
      "reportUrl": "/benchmark/reports/camera-04.report.json",
      "reportSha256": "7ee4be633f189b0b6fd88470450c12fe02f8c6ecc9fcaa168c9f76151a63ffb1",
      "reviewFile": "backend/benchmarks/reviews/camera-04.review.json",
      "reviewUrl": "/benchmark/reviews/camera-04.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded camera-01 and converted to WebP quality 82 while retaining its test EXIF.",
      "expectedEvidence": "Retained EXIF is detected after WebP conversion",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "ai-01",
      "category": "AI original export",
      "title": "AI provenance-marker baseline",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/ai-01.png",
      "inputUrl": "/benchmark/inputs/ai-01.png",
      "inputSha256": "708d09c980299389c8a8d2553944f88460d610470dc6a38289baff8d69ed9858",
      "reportFile": "backend/benchmarks/reports/ai-01.report.json",
      "reportUrl": "/benchmark/reports/ai-01.report.json",
      "reportSha256": "40e8bc54cd73157fc6e6efd8c50658fddaa5f9224b3386508d42023355253918",
      "reviewFile": "backend/benchmarks/reviews/ai-01.review.json",
      "reviewUrl": "/benchmark/reviews/ai-01.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Project-owned PNG with explicit OpenAI, trainedAlgorithmicMedia, and c2pa marker-only text chunks.",
      "expectedEvidence": "OpenAI and trainedAlgorithmicMedia markers are detected",
      "conclusion": "OpenAI/C2PA-style markers were found, but the C2PA signature has not been verified in this runtime.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "openai_marker_unverified",
      "c2paStatus": "verifier_unavailable_marker_detected",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "ai-02",
      "category": "AI original export",
      "title": "AI marker with metadata retained",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/ai-02.png",
      "inputUrl": "/benchmark/inputs/ai-02.png",
      "inputSha256": "387d665a504caed06e3bfe602a116af8b76bc32c3ea4ba4d86df0cebc57f21a1",
      "reportFile": "backend/benchmarks/reports/ai-02.report.json",
      "reportUrl": "/benchmark/reports/ai-02.report.json",
      "reportSha256": "1810175bc6d9e88dd7589262ad39f5d09d59e81e30e0256b368ad82358bb5265",
      "reviewFile": "backend/benchmarks/reviews/ai-02.review.json",
      "reviewUrl": "/benchmark/reviews/ai-02.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Project-owned PNG with an XMP-shaped text chunk retaining OpenAI, trainedAlgorithmicMedia, and c2pa strings.",
      "expectedEvidence": "OpenAI, XMP, and trainedAlgorithmicMedia markers are detected",
      "conclusion": "OpenAI/C2PA-style markers were found, but the C2PA signature has not been verified in this runtime.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "openai_marker_unverified",
      "c2paStatus": "verifier_unavailable_marker_detected",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "ai-03",
      "category": "AI original export",
      "title": "AI-style XMP marker fixture",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/ai-03.jpg",
      "inputUrl": "/benchmark/inputs/ai-03.jpg",
      "inputSha256": "ed8e1a899a6abb500fa0c682a9227aa83d9a8f79308970458d613b7f0f9fb56d",
      "reportFile": "backend/benchmarks/reports/ai-03.report.json",
      "reportUrl": "/benchmark/reports/ai-03.report.json",
      "reportSha256": "6307821372cd7636567f955145a6be02858df7d2572cc145946889c726ed6149",
      "reviewFile": "backend/benchmarks/reviews/ai-03.review.json",
      "reviewUrl": "/benchmark/reviews/ai-03.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Project-owned JPEG with a controlled XMP-shaped AI marker appended after EOI; no signed manifest.",
      "expectedEvidence": "XMP and trainedAlgorithmicMedia markers are detected",
      "conclusion": "AI-related provenance markers were found, but they are not a definitive attribution by themselves.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "ai-04",
      "category": "AI original export",
      "title": "AI-style byte marker fixture",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/ai-04.webp",
      "inputUrl": "/benchmark/inputs/ai-04.webp",
      "inputSha256": "2932be92998a9a9b39eedcf6234fcee92563334f004dcd2b96eadc730cacd8b8",
      "reportFile": "backend/benchmarks/reports/ai-04.report.json",
      "reportUrl": "/benchmark/reports/ai-04.report.json",
      "reportSha256": "4b417e73571911dbe37bb9192a73747fab6c02178490dd63fd40d85ff07f621b",
      "reviewFile": "backend/benchmarks/reviews/ai-04.review.json",
      "reviewUrl": "/benchmark/reviews/ai-04.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Project-owned WebP with controlled XMP and trainedAlgorithmicMedia byte markers appended after the RIFF payload.",
      "expectedEvidence": "Raw XMP and trainedAlgorithmicMedia byte markers are detected",
      "conclusion": "AI-related provenance markers were found, but they are not a definitive attribution by themselves.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "copy-01",
      "category": "Processed copy",
      "title": "Screenshot-style metadata loss",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/copy-01.png",
      "inputUrl": "/benchmark/inputs/copy-01.png",
      "inputSha256": "baf98a932dd0057b6aae3f4359bb94a31fa411fb336bafbf25e025c487af5fe3",
      "reportFile": "backend/benchmarks/reports/copy-01.report.json",
      "reportUrl": "/benchmark/reports/copy-01.report.json",
      "reportSha256": "3b5314d56e79eb0112aadcfc19b2d8d519798f3b066a824bb60f48ececf2902d",
      "reviewFile": "backend/benchmarks/reviews/copy-01.review.json",
      "reviewUrl": "/benchmark/reviews/copy-01.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded ai-01 pixels and saved as a new PNG without source text chunks, modeling screenshot metadata loss.",
      "expectedEvidence": "Source provenance markers are absent after screenshot-style save",
      "conclusion": "The frequency score is above the configured reference threshold, which is a supportive signal only.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "frequency_suspicious",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "copy-02",
      "category": "Processed copy",
      "title": "Social upload-style recompression",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/copy-02.jpg",
      "inputUrl": "/benchmark/inputs/copy-02.jpg",
      "inputSha256": "e629a515442e1f1db4cd6668b560db03a130f1e9360bbc9e52b6f70d54705be1",
      "reportFile": "backend/benchmarks/reports/copy-02.report.json",
      "reportUrl": "/benchmark/reports/copy-02.report.json",
      "reportSha256": "a32ae4234b5a71f71cacae3479a4cfeb2e5b347795ea1735c63b913f617d1dab",
      "reviewFile": "backend/benchmarks/reviews/copy-02.review.json",
      "reviewUrl": "/benchmark/reviews/copy-02.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded ai-03 pixels and recompressed as JPEG quality 58, dropping the appended marker.",
      "expectedEvidence": "Appended source markers are absent after recompression",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "copy-03",
      "category": "Processed copy",
      "title": "Metadata-stripped copy",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/copy-03.jpg",
      "inputUrl": "/benchmark/inputs/copy-03.jpg",
      "inputSha256": "c291b5a431bf51cab21d7a94b7fc89d406a1aaccd97952c71b8bde6e4c8129e6",
      "reportFile": "backend/benchmarks/reports/copy-03.report.json",
      "reportUrl": "/benchmark/reports/copy-03.report.json",
      "reportSha256": "a26f8b192b2b6a29d4c8f32f714794a0adda18137081b77093b0af8d0b2d37fc",
      "reviewFile": "backend/benchmarks/reviews/copy-03.review.json",
      "reviewUrl": "/benchmark/reviews/copy-03.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded camera-01 pixels and saved as JPEG quality 88 without EXIF.",
      "expectedEvidence": "Camera identity EXIF is absent after stripping",
      "conclusion": "The image has camera-like supporting evidence and no strong AI provenance marker was detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "camera_like",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "copy-04",
      "category": "Processed copy",
      "title": "Resized and converted copy",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/copy-04.webp",
      "inputUrl": "/benchmark/inputs/copy-04.webp",
      "inputSha256": "bb9df1dbbf57919d13cbb579cd24d4b64aa13a1cdd0afd56c5600e2a7ecfd1e3",
      "reportFile": "backend/benchmarks/reports/copy-04.report.json",
      "reportUrl": "/benchmark/reports/copy-04.report.json",
      "reportSha256": "8c6809f4200c3f1b3bf669e41620b0ea82c40b4fae697607d35de69efc60ab99",
      "reviewFile": "backend/benchmarks/reviews/copy-04.review.json",
      "reviewUrl": "/benchmark/reviews/copy-04.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Decoded ai-02 pixels, resized to 320x240, and saved as WebP quality 70 without metadata.",
      "expectedEvidence": "Source provenance markers are absent after resize/convert",
      "conclusion": "The frequency score is above the configured reference threshold, which is a supportive signal only.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "frequency_suspicious",
      "c2paStatus": "absent",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    },
    {
      "id": "c2pa-01",
      "category": "C2PA integrity",
      "title": "Trusted manifest expectation",
      "source": "Content Authenticity Initiative c2patool v0.26.67 distribution sample; dual Apache-2.0/MIT project",
      "license": "Apache-2.0/MIT upstream",
      "inputFile": "backend/benchmarks/inputs/c2pa-01.jpg",
      "inputUrl": "/benchmark/inputs/c2pa-01.jpg",
      "inputSha256": "5f57bc22ad54aab1228874e831a6feb5514e5875307945c4e4b11aae6c53e8b7",
      "reportFile": "backend/benchmarks/reports/c2pa-01.report.json",
      "reportUrl": "/benchmark/reports/c2pa-01.report.json",
      "reportSha256": "5c60990a429967fd19c61de0ff7c4dd201c2fc1a708b2cd8175fe68f97f0e741",
      "reviewFile": "backend/benchmarks/reviews/c2pa-01.review.json",
      "reviewUrl": "/benchmark/reviews/c2pa-01.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Unmodified c2patool v0.26.67 sample/C.jpg, evaluated with its sample end-entity allowed list.",
      "expectedEvidence": "Signature, trust, and asset binding all validate",
      "conclusion": "The manifest signature and asset binding validate under the recorded benchmark allow-list policy.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "valid_signature",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "c2patool 0.26.67",
      "trustPolicy": "End-entity allow list SHA-256 7973400b5b75c3f8dd1f1c76f18d0c862842cbedeeb13b1fbb71e1e541d3f5f0"
    },
    {
      "id": "c2pa-02",
      "category": "C2PA integrity",
      "title": "Manifest present but trust unresolved",
      "source": "Content Authenticity Initiative example-assets; MIT License",
      "license": "MIT",
      "inputFile": "backend/benchmarks/inputs/c2pa-02.jpg",
      "inputUrl": "/benchmark/inputs/c2pa-02.jpg",
      "inputSha256": "bdc5c19d4211d9c9f9f8dce5bf4e4dec29e9b32e308ff12a60979481e928154f",
      "reportFile": "backend/benchmarks/reports/c2pa-02.report.json",
      "reportUrl": "/benchmark/reports/c2pa-02.report.json",
      "reportSha256": "c34f7b6ef510baeadc247e47fcffd6dbb946a300efc94c3e7c26db43ac3b6371",
      "reviewFile": "backend/benchmarks/reviews/c2pa-02.review.json",
      "reviewUrl": "/benchmark/reviews/c2pa-02.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Unmodified CAI example-assets Firefly_tabby_cat.jpg, evaluated without a configured signer trust list.",
      "expectedEvidence": "Manifest signature is intact but signer trust is unresolved",
      "conclusion": "The signature is intact, but the signer is not trusted under this case's empty trust policy.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "verifier_error_marker_detected",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "c2patool 0.26.67",
      "trustPolicy": "No trust anchors or signer allow list configured."
    },
    {
      "id": "c2pa-03",
      "category": "C2PA integrity",
      "title": "Asset-binding mismatch expectation",
      "source": "Content Authenticity Initiative c2patool v0.26.67 distribution sample; dual Apache-2.0/MIT project",
      "license": "Apache-2.0/MIT upstream",
      "inputFile": "backend/benchmarks/inputs/c2pa-03.jpg",
      "inputUrl": "/benchmark/inputs/c2pa-03.jpg",
      "inputSha256": "49058d24bf9f02312833b17db4cc1162dfc70c6b1aef36a428fcb1ea0afe4033",
      "reportFile": "backend/benchmarks/reports/c2pa-03.report.json",
      "reportUrl": "/benchmark/reports/c2pa-03.report.json",
      "reportSha256": "a45849991305f391c8fb25230afffb9626bc7f5f7e75cba3baa0f5b666979b96",
      "reviewFile": "backend/benchmarks/reviews/c2pa-03.review.json",
      "reviewUrl": "/benchmark/reviews/c2pa-03.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Derived from c2pa-01 by flipping bit 0 of JPEG entropy byte offset 952; file remains decodable.",
      "expectedEvidence": "Signed asset binding mismatch is detected",
      "conclusion": "The verifier found a signed-manifest asset-binding mismatch; this controlled mutation is detected.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "asset_hash_mismatch",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "c2patool 0.26.67",
      "trustPolicy": "End-entity allow list SHA-256 7973400b5b75c3f8dd1f1c76f18d0c862842cbedeeb13b1fbb71e1e541d3f5f0"
    },
    {
      "id": "c2pa-04",
      "category": "C2PA integrity",
      "title": "No manifest / marker-only expectation",
      "source": "Img2det project-owned controlled fixture",
      "license": "Project-owned",
      "inputFile": "backend/benchmarks/inputs/c2pa-04.png",
      "inputUrl": "/benchmark/inputs/c2pa-04.png",
      "inputSha256": "a1d8bca10fec13797bb32c1c39712c4c8311c3eed9a67dbb70e013e5772b0c41",
      "reportFile": "backend/benchmarks/reports/c2pa-04.report.json",
      "reportUrl": "/benchmark/reports/c2pa-04.report.json",
      "reportSha256": "e2489f9e4dafbe6c33ae63dcae4f53e44fb89712582d652c150761af63fb9ac8",
      "reviewFile": "backend/benchmarks/reviews/c2pa-04.review.json",
      "reviewUrl": "/benchmark/reviews/c2pa-04.review.json",
      "reviewStatus": "human_approved",
      "reportStatus": "Evidence generated; maintainer approved",
      "preparation": "Project-owned PNG containing a literal c2pa text marker but no C2PA/JUMBF manifest.",
      "expectedEvidence": "Literal marker is reported without a verified manifest",
      "conclusion": "AI-related provenance markers were found, but they are not a definitive attribution by themselves.",
      "limitation": "Controlled fixture result only; it does not measure real-world prevalence or detector accuracy.",
      "evidenceLevel": "other_ai_provenance_marker",
      "c2paStatus": "verifier_unavailable_marker_detected",
      "runDate": "2026-08-03",
      "backendVersion": "3f893b11e758f61eb63c380052e7c0c47a06bfcc",
      "verifierVersion": "not invoked",
      "trustPolicy": "No C2PA verifier invoked for this controlled non-C2PA/marker-only case."
    }
  ]
}