arXiv subjects

Sam Ryan

Publications and source records attributed to Sam Ryan.

3 recordsLinked to original sources

arXiv2026

Semantic Non-Assembly: Privacy by Architectural Inertness Under Component Exposure

Existing privacy frameworks emphasize confidentiality, access control, appropriate information flow, or statistical disclosure limitation. We introduce a complementary class of privacy guarantee (Semantic Non-Assembly) in which privacy is characterized not by the difficulty of achieving exposure but by the information yield of exposure when it occurs. SNA prevents evaluation of a designated predicate by preventing any sub-threshold coalition from assembling a sufficient assignment to its input domain. An architecture satisfies Semantic Non-Assembly when no coalition of fewer than a defined threshold of components can assemble such an assignment: complete exposure and decryption of any sub-threshold component yields no actionable data. In the base protocol, the guarantee is structural: it operates through architecture, not policy, and its privacy properties degrade predictably under component compromise rather than collapsing at a single point. The reference instantiation combines this structural guarantee with audited organizational constraints, as characterized in Appendix A. This paper formalizes the guarantee and establishes four ProVerif-verified properties: Device Non-Correlation, Registry Observer Non-Identification, Submission Server Blindness, and Active Defense Gate correctness, the first three through a two-channel provenance architecture. The Birthmark Standard instantiates the guarantee on constrained capture hardware, demonstrating deployability where ZK-based approaches are computationally infeasible. All formal properties and scope limitations are documented in Appendix A.

cs.CR↗

arXiv2026

Durable Evaluation Framework: Adversarial Arbitration for Sycophancy Reduction in Large Language Models

RLHF-trained models are systematically biased toward agreement over accuracy, a structural property of the training process. We present Durable Evaluation Framework (DEF) Arbitration, a multi-agent architecture that mitigates identity-framed sycophancy by arbitrating between two models tuned to opposing DEFs, with a pragmatist synthesizer evaluating both arguments blind to their origins. This paper evaluates a prompt-based instantiation of DEF Arbitration. The key mechanisms are static DEF tuning, identity stripping before synthesis, single-round independent argumentation, and blind arbitration. We evaluate five instantiations on 200 stratified questions from SycophancyEval. All tested DEF variants (AnCifer, DeWin, FeynStein, BurGal, Trident) significantly outperform the single-model baseline (18.5%) and instructed-opposition baseline (29.0%), with DeWin achieving 48.5% accuracy (z=6.36, p<0.001 versus both). The variants are not significantly different from each other at n=200. The BurGal variant achieves 53.0% but functions as an architectural validity check; its consensus/heterodox axis structurally favors the heterodox model on every benchmark question. A pre-training floor affects an estimated 40% of questions; fine-tuned DEF models are the identified next step.

cs.CL↗

arXiv2026

The Birthmark Standard: Privacy-Preserving Photo Authentication via Hardware Roots of Trust and Consortium Blockchain

The rapid advancement of generative AI systems has collapsed the credibility landscape for photographic evidence. Modern image generation models produce photorealistic images undermining the evidentiary foundation upon which journalism and public discourse depend. Existing authentication approaches, such as the Coalition for Content Provenance and Authenticity (C2PA), embed cryptographically signed metadata directly into image files but suffer from two critical failures: technical vulnerability to metadata stripping during social media reprocessing, and structural dependency on corporate-controlled verification infrastructure where commercial incentives may conflict with public interest. We present the Birthmark Standard, an authentication architecture leveraging manufacturing-unique sensor entropy from non-uniformity correction (NUC) maps and PRNU patterns to generate hardware-rooted authentication keys. During capture, cameras create anonymized authentication certificates proving sensor authenticity without exposing device identity via a key table architecture maintaining anonymity sets exceeding 1,000 devices. Authentication records are stored on a consortium blockchain operated by journalism organizations rather than commercial platforms, enabling verification that survives all metadata loss. We formally verify privacy properties using ProVerif, proving observational equivalence for Manufacturer Non-Correlation and Blockchain Observer Non-Identification under Dolev-Yao adversary assumptions. The architecture is validated through prototype implementation using Raspberry Pi 4 hardware, demonstrating the complete cryptographic pipeline. Performance analysis projects camera overhead below 100ms and verification latency below 500ms at scale of one million daily authentications.

cs.CR↗