openssl/openssl
Feb 2025 – Apr 2026
4 Months active
Languages Used
AssemblyCPerl
Technical Skills
Assembly Language ProgrammingCryptographyEmbedded SystemsPerformance Optimizationassembly languagecryptography
Danny Tsen
PROFILE
Danny Tsen
Contributed to the openssl/openssl repository by engineering cryptographic and performance enhancements for PowerPC platforms. Delivered a timing side-channel mitigation for the P-384 curve, replacing specialized Montgomery multiplication with a generalized assembly implementation to strengthen security and maintainability. Addressed PPC64LE AES/GCM correctness by restoring VSX registers, aligning cryptographic operations with Linux kernel expectations. Improved PPC64 big-endian build stability by refining ABI directives in the build system. Developed a PPC64LE-specific ML-KEM NTT assembly optimization, achieving substantial throughput gains. Work demonstrated expertise in assembly language, C, and build systems, with a focus on secure coding, cross-platform compatibility, and rigorous code review.
Overall Statistics
Feature vs Bugs
25%Features
Repository Contributions
4Total
Bugs
3
Commits
4
Features
1
Lines of code
5,359
Activity Months4
Your Network
547 peopleShared Repositories
365
Work History
April 2026
1 Commits • 1 Features
Apr 1, 2026April 2026 openssl/openssl monthly summary Key features delivered: PPC64LE-specific MLKEM NTT performance optimization with assembly support for both NTT and inverse NTT, targeting ISA 2.07+. Added PPC64LE assembly files (asm/mlkem_ntt_ppc64le.S, asm/mlkem_intt_ppc64le.S) and updated build system to enable arch-specific MLKEM_NTT_ASM paths. Major bugs fixed: No notable bugs fixed this month for this repository. Overall impact and accomplishments: Achieved ~1.9x speedup in ML-KEM NTT/encaps/decaps throughput on PPC64LE versus the baseline C implementation, enhancing cryptographic operations in PPC64LE environments and improving TLS-related KEM performance. Builds and tests validated the improvement, contributing to better performance-per-watt and lower latency for PQC workflows. Technologies/skills demonstrated: Assembly optimization for PPC64LE, cross-architecture performance engineering, performance benchmarking (throughput improvements), C/assembly integration, build system updates, and collaboration through code review and merge processes.
1 Commits • 1 Features
Apr 1, 2026April 2026 openssl/openssl monthly summary Key features delivered: PPC64LE-specific MLKEM NTT performance optimization with assembly support for both NTT and inverse NTT, targeting ISA 2.07+. Added PPC64LE assembly files (asm/mlkem_ntt_ppc64le.S, asm/mlkem_intt_ppc64le.S) and updated build system to enable arch-specific MLKEM_NTT_ASM paths. Major bugs fixed: No notable bugs fixed this month for this repository. Overall impact and accomplishments: Achieved ~1.9x speedup in ML-KEM NTT/encaps/decaps throughput on PPC64LE versus the baseline C implementation, enhancing cryptographic operations in PPC64LE environments and improving TLS-related KEM performance. Builds and tests validated the improvement, contributing to better performance-per-watt and lower latency for PQC workflows. Technologies/skills demonstrated: Assembly optimization for PPC64LE, cross-architecture performance engineering, performance benchmarking (throughput improvements), C/assembly integration, build system updates, and collaboration through code review and merge processes.
April 2026
January 2026
1 Commits
Jan 1, 2026Monthly summary for openssl/openssl development in 2026-01 focused on PPC64 Big-Endian ABI build stability and cross-ABI integrity. Implemented a precise build fix by removing the .localentry directive to prevent mixing ELFv1 and ELFv2 ABI directives, resolving PPC64 big-endian build failures. The change is tracked in commit 5aaa7e5fdc59e88a13d2911cb86d814d4e2669da and merged from PR 29827, addressing issue #29815. This work enhances portability, CI reliability, and long-term maintenance for PPC64 BE platforms.
January 2026
1 Commits
Jan 1, 2026Monthly summary for openssl/openssl development in 2026-01 focused on PPC64 Big-Endian ABI build stability and cross-ABI integrity. Implemented a precise build fix by removing the .localentry directive to prevent mixing ELFv1 and ELFv2 ABI directives, resolving PPC64 big-endian build failures. The change is tracked in commit 5aaa7e5fdc59e88a13d2911cb86d814d4e2669da and merged from PR 29827, addressing issue #29815. This work enhances portability, CI reliability, and long-term maintenance for PPC64 BE platforms.
October 2025
1 Commits
Oct 1, 2025OpenSSL 2025-10: Delivered a critical PPC64LE bug fix for AES/GCM by restoring VSX registers in the encryption/decryption path. This corrects behavior, improves performance on PPC64LE, and ensures Linux kernel compatibility. Implemented in commit ebd690b1eb0d95c6784e2f36dd86d72670b82794 and merged from PR28990 with peer reviews by Dmitry Belyavskiy and Tomas Mraz; aligns with kernel patterns for stability and security.
1 Commits
Oct 1, 2025OpenSSL 2025-10: Delivered a critical PPC64LE bug fix for AES/GCM by restoring VSX registers in the encryption/decryption path. This corrects behavior, improves performance on PPC64LE, and ensures Linux kernel compatibility. Implemented in commit ebd690b1eb0d95c6784e2f36dd86d72670b82794 and merged from PR28990 with peer reviews by Dmitry Belyavskiy and Tomas Mraz; aligns with kernel patterns for stability and security.
October 2025
February 2025
1 Commits
Feb 1, 2025February 2025 monthly summary for openssl/openssl focusing on security hardening and performance in cryptographic operations. Key features delivered: a robust timing side-channel mitigation for the P-384 curve on PowerPC, including replacing a specific Montgomery multiplication with a more general implementation and introducing new assembly optimizations for field element operations to enhance security and maintainability. Major bugs fixed: fix Minerva timing side-channel signal for P-384 on PPC, consolidated in commit 85cabd94958303859b1551364a609d4ff40b67a5. Overall impact and accomplishments: strengthened cryptographic resilience on PPC platforms, improved maintainability of critical code paths, and reinforced OpenSSL’s security posture for production deployments. Technologies/skills demonstrated: cryptographic algorithm implementation, side-channel mitigation techniques, PPC assembly optimizations, cross-platform development, code review, testing, and Git-based version control.
February 2025
1 Commits
Feb 1, 2025February 2025 monthly summary for openssl/openssl focusing on security hardening and performance in cryptographic operations. Key features delivered: a robust timing side-channel mitigation for the P-384 curve on PowerPC, including replacing a specific Montgomery multiplication with a more general implementation and introducing new assembly optimizations for field element operations to enhance security and maintainability. Major bugs fixed: fix Minerva timing side-channel signal for P-384 on PPC, consolidated in commit 85cabd94958303859b1551364a609d4ff40b67a5. Overall impact and accomplishments: strengthened cryptographic resilience on PPC platforms, improved maintainability of critical code paths, and reinforced OpenSSL’s security posture for production deployments. Technologies/skills demonstrated: cryptographic algorithm implementation, side-channel mitigation techniques, PPC assembly optimizations, cross-platform development, code review, testing, and Git-based version control.
Activity
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Quality Metrics
Correctness100.0%
Maintainability85.0%
Architecture95.0%
Performance95.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
AssemblyCPerl
Technical Skills
Assembly Language ProgrammingCryptographyEmbedded SystemsPerformance Optimizationassembly languageassembly optimizationbuild systemscryptographylow-level programmingperformance optimizationperformance tuning
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