arXiv subjects

Christopher M. Frost

Publications and source records attributed to Christopher M. Frost.

2 recordsLinked to original sources

arXiv2026

A Reproducibility Protocol for Cross-Implementation Evaluation of Post-Quantum ACVP Test Vectors

Independent implementations of a cryptographic standard should reproduce the same known-answer results, yet agreement is meaningful only when the corpus, revisions, public interfaces, exclusions, and evidence are precisely stated. This study defines a product-neutral reproducibility protocol for three public implementations of NIST ML-KEM against a pinned public Automated Cryptographic Validation Protocol corpus. Protocol v2 freezes provider-specific capabilities, applies one validation-error taxonomy symmetrically, preserves every selected case, and separates bytes, validation verdicts, unsupported operations, and adapter errors. The source-built experiment evaluated @noble/post-quantum 0.7.0, liboqs 0.16.0, and Go 1.26.4. Across three repetitions, the required Cartesian product comprised 2,160 base records: all 1,650 declared executable evaluations matched the NIST oracle, and all 510 unsupported records matched Go's predeclared capability boundary. Pairwise agreement was complete on every executable overlap: 720 of 720 noble-liboqs records and 210 of 210 records for each Go pairing. A separate keyGen-ek-projection diagnostic matched all 150 Go encapsulation-key projections without counting them as full key generation. Three frozen controls independently exercised byte comparison, verdict comparison, and malformed-response error separation; each produced its exact predeclared outcome. No base failure, adapter error, or status instability occurred. The evidence establishes bounded author-run repeatability and exposes a practical standards gap: public ML-KEM packages provide materially different deterministic and validation-test surfaces. Independent external reproduction remains unobserved. The results do not establish certification, exhaustive correctness, side-channel resistance, secure integration, or production assurance.

cs.CR↗

arXiv2026

Withholding the Completing Chunk: Exact Release-Boundary Equivalence for Production Streaming Guardrails

Streaming language-model output creates an enforcement boundary: a control that detects a prohibited pattern after releasing its completing chunk cannot recall it. We study a production policy in which each ordered family is the conjunction of two regular-language predicates. Incremental matching is classical. The problem is exact composition at release time across arbitrary chunk partitions, including end-of-prefix word boundaries that can change on extension. We define an ASCII-explicit policy grammar, compile each predicate to a persistent nondeterministic finite automaton (NFA), distinguish stable from provisional assertion state, apply document-order family priority, and check the decision before releasing each chunk. We show that the resulting monitor is release-boundary equivalent to an absorbing cumulative oracle for every policy in the declared grammar. Production Python and TypeScript implementations were evaluated on 101,653 partitioned cases; a public surrogate added 100,345 cases. Both campaigns produced zero oracle, cross-runtime, or intended-family mismatches. In a frozen neutral-output profile, the memoized incremental and native-regex cumulative slopes at 64-character chunks were 0.973 and 1.976. At 16,384 characters the incremental median was 30.2 ms versus 96.6 ms for native cumulative scanning at that chunk size. Native regex remained faster at 512-character chunks (12.4 versus 29.4 ms), exposing the constant-factor crossover rather than hiding it. A shared per-stream cache cap and 129-symbol alphabet bound optimization state; the campaign peaked at 364 of 4,096 without bypass. The result is policy conformance for a deterministic backstop, not evidence of semantic safety or policy completeness.

cs.CR↗