{"data":{"id":"a1b90917-b39f-4819-851a-0e380a8f995f","title":"Auditor-Assisted Summary-Channel Verification for Hosted LLM Identity Substitution","summary":"SUMMARK is an auditor-assisted watermarking framework that verifies whether a hosted LLM served a claimed identity, using user-visible reasoning summaries as a keyed audit surface. Auditors enroll identities and calibrate per-identity thresholds before deployment, and audits rely only on the released output. Across model families, scales and task domains, the method reliably detects cross-family and cross-scale substitutions at low false-positive rates while preserving answer quality, though the authors also report failure boundaries under rewriting stress tests and text-only spoofing.","solution":"N/A -- no mitigation discussed in source.","labels":["security","research"],"sourceUrl":"https://arxiv.org/abs/2610.25982v1","publishedAt":"2026-10-19T08:09:11.000Z","cveId":null,"cweIds":null,"cvssScore":null,"cvssSeverity":null,"severity":"info","attackType":["model_evasion"],"issueType":"research","affectedPackages":null,"affectedPackageNames":null,"affectedPackageRefs":null,"affectedVendors":[],"affectedVendorsRaw":["hosted LLM services","reasoning summaries"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":null,"epssScore":null,"epssCheckedAt":null,"kevDateAdded":null,"advisoryAliases":null,"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":null,"disclosureDate":"2026-10-19T08:09:11.000Z","capecIds":null,"crossRefCount":0,"attackSophistication":"advanced","impactType":["integrity"],"aiComponentTargeted":"api","llmSpecific":true,"classifierConfidence":0.9,"researchCategory":"preprint","atlasIds":null}}