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Rod Chapman

PROFILE

Rod Chapman

Rod Chapman developed and maintained core cryptographic libraries in the pq-code-package/mlkem-c-aarch64 and mldsa-native repositories, focusing on formal verification, performance optimization, and build automation. He implemented CBMC-based proofs and SMT solver integration to strengthen correctness and security, refactored C and ARM assembly code for safer APIs and improved maintainability, and modernized build systems using Makefile and Nix. His work included automating cross-platform builds, enforcing code style consistency, and enhancing debugging workflows. By addressing verification stability and macro hygiene, Rod delivered robust, reproducible cryptographic components, demonstrating deep expertise in C programming, formal verification, and low-level optimization for secure software.

Overall Statistics

Feature vs Bugs

82%Features

Repository Contributions

65Total
Bugs
6
Commits
65
Features
27
Lines of code
28,216
Activity Months11

Work History

October 2025

2 Commits • 2 Features

Oct 1, 2025

Month: 2025-10. Focus: macro stability improvements across two codebases by migrating macro-generated variable names from __LINE__ to __COUNTER__, plus minor documentation correction. Key features delivered: mlkem-c-aarch64: replaced __LINE__-based macro variable generation with __COUNTER__ for generated names, improving proof stability against minor code changes; commit 17bdc7df125da56a5f6e5f24c229a5c7b6f7e732. mldsa-native: refactored macro definitions to use COUNTER for quantified variable naming, preventing changes from altering names and improving proof reliability; commit 46ecf314a111f081c84ea3ad171fecaa26063ca2. Major bugs fixed: reduced fragility of proofs due to __LINE__-based naming; improved documentation alignment in proof_guide.md. Overall impact and accomplishments: higher proof stability, reduced maintenance churn, and cross-repo consistency; demonstrated macro-level correctness improvements with clear business value. Technologies/skills demonstrated: C macro programming (COUNTER), preprocessor-driven refactoring, cross-repo code hygiene, and documentation governance.

September 2025

7 Commits • 3 Features

Sep 1, 2025

Performance-driven monthly summary for 2025-09: Strengthened formal verification and debugging capabilities across two repos (mlkem-c-aarch64 and mldsa-native). Implemented explicit buffer bounds and guaranteed malloc failure behavior in mlkem-native CBMC proofs; added SMT file generation targets and provenance reporting for multiple provers; enhanced CBMC debugging workflows in mldsa-native with SMT-only generation and a slice-formula option; removed the --no-array-field-sensitivity flag to stabilize proof times. Result: improved safety guarantees, traceability, and cross-prover comparability, enabling faster issue detection and lower verification risk.

July 2025

8 Commits • 5 Features

Jul 1, 2025

July 2025 highlights API modernization and formal verification across two repositories, delivering safer cryptographic primitives, clearer interfaces, and more deterministic verification. Key outcomes include API refactors, enhanced proofs, and configurable verification tooling that reduce risk and accelerate validation cycles.

June 2025

5 Commits • 1 Features

Jun 1, 2025

June 2025 focused on cleaning up verification-related debt and harmonizing builds for next-gen architectures across two PQ code packages. Key outcomes include removing CBMC workarounds post-upgrade, enhancing verifier safety through API-level refactors, and enabling Neoverse-N1 optimization with updated toolchains and build configurations.

May 2025

12 Commits • 3 Features

May 1, 2025

May 2025 monthly performance focusing on formal verification improvements for cryptographic libraries and tooling modernization across two repositories. Deliverables emphasize faster, more reliable proofs, better reporting, and licensing clarity, with proven proficiency in formal methods and build tooling.

April 2025

10 Commits • 3 Features

Apr 1, 2025

April 2025 monthly summary focusing on key business- and technically-focused accomplishments across two repositories. Delivered code quality and compliance enhancements with a foundation for future reliability improvements.

March 2025

3 Commits • 2 Features

Mar 1, 2025

March 2025 monthly summary focusing on delivering performance enhancements, robustness, and maintainability across two repositories: mlkem-c-aarch64 and mldsa-native. Key work included AArch64 backend optimizations and macro standardization, formal verification proofs for make_hint, and improvements to the build and test workflow. No distinct major bug fixes were reported; the month emphasized performance, correctness, and reproducibility.

February 2025

4 Commits • 3 Features

Feb 1, 2025

February 2025 monthly summary for repository pq-code-package/mlkem-c-aarch64. Delivered performance optimizations and process improvements for AArch64 back-end components, focusing on INTT/NTT performance, naming consistency, and build automation to enable reproducible optimizations with SLOTHLY.

January 2025

2 Commits • 1 Features

Jan 1, 2025

January 2025: Delivered targeted improvements to the mlkem-c-aarch64 pipeline, focusing on visibility of proof results and macOS execution reliability. The changes improved debugging efficiency, reduced environment-related failures, and contributed to a more stable development and CI experience for the repository.

December 2024

1 Commits

Dec 1, 2024

December 2024 monthly summary for the mlkem-c-aarch64 repository focused on cross-platform build reliability for the benchmark suite. Delivered macOS GCC 14 build compatibility by adjusting compiler behavior to avoid -Wpedantic errors in void* to function pointer conversions used by dlsym, enabling the benchmark tests to compile and run. This fix removes a critical CI/build blocker and tightens cross-platform test coverage.

November 2024

11 Commits • 4 Features

Nov 1, 2024

November 2024: Expanded formal verification coverage and proof workflow efficiency for pq-code-package/mlkem-c-aarch64. Delivered CBMC-based proofs and contracts for message conversion and cryptographic primitives, extended verification to core primitives (indcpa_dec, unpack_ciphertext, FIPS-202 hashes), improved proof generation speed, and completed contract simplifications for maintainability. These efforts strengthen correctness, security guarantees, and development velocity for MLKEM components, enhancing reliability for deployment and certification readiness.

Activity

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Quality Metrics

Correctness92.4%
Maintainability89.8%
Architecture88.2%
Performance80.8%
AI Usage20.0%

Skills & Technologies

Programming Languages

AssemblyCC++MakefileMarkdownNixPythonShell

Technical Skills

ARM ArchitectureARM AssemblyAlgorithm ImplementationAlgorithm optimizationAssembly LanguageAssembly Language ProgrammingAssembly language optimizationBuild AutomationBuild SystemBuild System ConfigurationBuild System ManagementBuild SystemsBuild systemsCC Programming

Repositories Contributed To

2 repos

Overview of all repositories you've contributed to across your timeline

pq-code-package/mlkem-c-aarch64

Nov 2024 Oct 2025
11 Months active

Languages Used

CC++MakefilePythonAssemblyMarkdownShellNix

Technical Skills

Build SystemsCC ProgrammingCBMCCode DocumentationCode Formatting

pq-code-package/mldsa-native

Mar 2025 Oct 2025
7 Months active

Languages Used

CMakefileMarkdownNixPython

Technical Skills

C ProgrammingCryptographyFormal VerificationAlgorithm ImplementationBuild systemsC programming

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