lowRISC/opentitan
Apr 2025 – Jul 2026
16 Months active
Languages Used
CJSONRustPythonStarlarkAssemblyMarkdownSystemVerilog
Technical Skills
C programmingembedded systemsfirmware developmentAssembly LanguageEmbedded SystemsFirmware Development
Siemen Dhooghe
PROFILE
Siemen Dhooghe
Over 16 months, contributed to the lowRISC/opentitan repository by developing and hardening security-critical firmware, cryptographic libraries, and penetration testing frameworks. Delivered features such as ROM_EXT secure boot validation, fault-injection simulation, and OTBN memory compression, using C, Python, and assembly language. Enhanced test automation and CI integration, expanded FPGA and hardware test coverage, and implemented robust cryptographic primitives with side-channel and fault-attack resistance. Applied modular design, build system configuration, and secure coding practices to improve reliability, maintainability, and compliance readiness. Addressed bugs and optimized performance, demonstrating depth in embedded systems, cryptography, and low-level programming across hardware and software boundaries.
Overall Statistics
Feature vs Bugs
73%Features
Repository Contributions
266Total
Bugs
49
Commits
266
Features
132
Lines of code
103,395
Activity Months16
Your Network
5097 peopleSame Organization
@google.com4997
Benedict OdaiMember
Craig IngramMember
KayyuriMember
Scott SuarezMember
Agent2Agent (A2A) BotMember
Andreas AbelMember
Aadi KapurMember
Aadish GoelMember
Aahil MehtaMember
Work History
July 2026
4 Commits • 2 Features
Jul 1, 2026July 2026 performance and technical summary for lowRISC/opentitan: Implemented two core OTBN improvements—LZ4-based memory compression/decompression and ELF header relocation support—strengthening memory efficiency, runtime performance, and link-time reliability for OTBN binaries.
4 Commits • 2 Features
Jul 1, 2026July 2026 performance and technical summary for lowRISC/opentitan: Implemented two core OTBN improvements—LZ4-based memory compression/decompression and ELF header relocation support—strengthening memory efficiency, runtime performance, and link-time reliability for OTBN binaries.
July 2026
June 2026
37 Commits • 18 Features
Jun 1, 2026June 2026 monthly summary for lowRISC/opentitan focusing on business value and technical achievement: OTBN security validation capabilities were expanded with a new fault-injection simulation target (otbn_fi_sim_test) enabling automated FI testing and TVLA leakage analysis. The crypto stack received extensive hardening and FI coverage across RSA, ECC (P-256/P-384), Ed25519, and 25519, including r=0 guard for ECC, redundant checks, and defenses against small-subgroup leakage. An OTBN RSA verify FI simulation was added to broaden coverage of critical verify paths. Deterministic test improvements were implemented via fixed iteration counts for FI tests and safer error semantics (OTCRYPTO_RECOV_ERR). Infrastructure and build hygiene were enhanced through packaging and performance changes (LZ4 dependency; streaming SHA2 for 25519), removal of VLAs, barriered cleanup, and hardened entropy and firmware-gdb status reporting. Overall, these changes strengthen security posture, increase validation coverage, reduce leakage risk, and improve compliance readiness and developer productivity.
June 2026
37 Commits • 18 Features
Jun 1, 2026June 2026 monthly summary for lowRISC/opentitan focusing on business value and technical achievement: OTBN security validation capabilities were expanded with a new fault-injection simulation target (otbn_fi_sim_test) enabling automated FI testing and TVLA leakage analysis. The crypto stack received extensive hardening and FI coverage across RSA, ECC (P-256/P-384), Ed25519, and 25519, including r=0 guard for ECC, redundant checks, and defenses against small-subgroup leakage. An OTBN RSA verify FI simulation was added to broaden coverage of critical verify paths. Deterministic test improvements were implemented via fixed iteration counts for FI tests and safer error semantics (OTCRYPTO_RECOV_ERR). Infrastructure and build hygiene were enhanced through packaging and performance changes (LZ4 dependency; streaming SHA2 for 25519), removal of VLAs, barriered cleanup, and hardened entropy and firmware-gdb status reporting. Overall, these changes strengthen security posture, increase validation coverage, reduce leakage risk, and improve compliance readiness and developer productivity.
May 2026
84 Commits • 53 Features
May 1, 2026Month 2026-05 summary focused on security hardening, robust verification, OTBN cryptolib improvements, and testing/documentation enhancements across the opentitan codebase. Delivered key cryptographic feature work, fault-injection mitigations, and testing/PI/CIC improvements while laying groundwork for future code-size reductions and FIPS readiness.
84 Commits • 53 Features
May 1, 2026Month 2026-05 summary focused on security hardening, robust verification, OTBN cryptolib improvements, and testing/documentation enhancements across the opentitan codebase. Delivered key cryptographic feature work, fault-injection mitigations, and testing/PI/CIC improvements while laying groundwork for future code-size reductions and FIPS readiness.
May 2026
April 2026
6 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for lowRISC/opentitan: Implemented security hardening and release controls across the crypto stack, with targeted fixes to prevent padding or overflow vulnerabilities. Notable commits include hardened arithmetic with reversibility tests (b32efe5d923e1947ebfc0e73020b4e091454faa3, e81fe08706c2e081b14fc71f8437893596355819), release flag for cryptolib (47fac86058f60ab78dfa277c4c433692f2da1c84), AES-KWP exp_pad size standardization and DRBG buffer sizing (4cb47230d01ac2dff589b22a85de6e623cc2aafc, 75f7d2fe44f2e3da01511f8d4f0a4c6e0cbbdd64), and AES-GCM tag length check (ee4aad73d4a193892cb6f8baa2354ec333dacaea). Impact: strengthened resistance to fault injections, safer release builds, and improved reliability and performance in critical crypto paths. Value: reduces deployment risk and reinforces cryptographic guarantees in OT repositories.
April 2026
6 Commits • 3 Features
Apr 1, 2026April 2026 monthly summary for lowRISC/opentitan: Implemented security hardening and release controls across the crypto stack, with targeted fixes to prevent padding or overflow vulnerabilities. Notable commits include hardened arithmetic with reversibility tests (b32efe5d923e1947ebfc0e73020b4e091454faa3, e81fe08706c2e081b14fc71f8437893596355819), release flag for cryptolib (47fac86058f60ab78dfa277c4c433692f2da1c84), AES-KWP exp_pad size standardization and DRBG buffer sizing (4cb47230d01ac2dff589b22a85de6e623cc2aafc, 75f7d2fe44f2e3da01511f8d4f0a4c6e0cbbdd64), and AES-GCM tag length check (ee4aad73d4a193892cb6f8baa2354ec333dacaea). Impact: strengthened resistance to fault injections, safer release builds, and improved reliability and performance in critical crypto paths. Value: reduces deployment risk and reinforces cryptographic guarantees in OT repositories.
March 2026
28 Commits • 14 Features
Mar 1, 2026March 2026 monthly work summary for lowRISC/opentitan focused on security buffer improvements, test infrastructure, and crypto library robustness. Delivered new tests and macros, strengthened cryptographic buffer handling, and expanded cryptographic test coverage to improve reliability and security posture.
28 Commits • 14 Features
Mar 1, 2026March 2026 monthly work summary for lowRISC/opentitan focused on security buffer improvements, test infrastructure, and crypto library robustness. Delivered new tests and macros, strengthened cryptographic buffer handling, and expanded cryptographic test coverage to improve reliability and security posture.
March 2026
February 2026
5 Commits • 3 Features
Feb 1, 2026February 2026 deliverables centered on strengthening the reliability of the Penetration Testing framework and reinforcing cryptographic data integrity in opentitan. Notable work includes fixes to the firmware override RNG test to run reliably without device resets, enhancements to KMAC/SHA3 testing, and integration of pointer-level integrity checks across DRBG, HMAC, and crypto buffers. These changes reduce test flakiness, improve security validation, and broaden testing coverage for cryptographic primitives.
February 2026
5 Commits • 3 Features
Feb 1, 2026February 2026 deliverables centered on strengthening the reliability of the Penetration Testing framework and reinforcing cryptographic data integrity in opentitan. Notable work includes fixes to the firmware override RNG test to run reliably without device resets, enhancements to KMAC/SHA3 testing, and integration of pointer-level integrity checks across DRBG, HMAC, and crypto buffers. These changes reduce test flakiness, improve security validation, and broaden testing coverage for cryptographic primitives.
January 2026
1 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for lowRISC/opentitan. Focused on stabilizing long-running pentest workflows by enhancing UART readouts. Delivered an initial timeout option for the read_response function to accommodate tests where operational time exceeds UART response time, reducing flakiness and enabling batched tests. Core change implemented in the pentest framework with commit 8ead9103b29be87a7d3c4009a6355ccfa7f1a869; Signed-off-by: Siemen Dhooghe. Overall impact includes more reliable data collection during security assessments and smoother automation of extended tests.
1 Commits • 1 Features
Jan 1, 2026January 2026 monthly summary for lowRISC/opentitan. Focused on stabilizing long-running pentest workflows by enhancing UART readouts. Delivered an initial timeout option for the read_response function to accommodate tests where operational time exceeds UART response time, reducing flakiness and enabling batched tests. Core change implemented in the pentest framework with commit 8ead9103b29be87a7d3c4009a6355ccfa7f1a869; Signed-off-by: Siemen Dhooghe. Overall impact includes more reliable data collection during security assessments and smoother automation of extended tests.
January 2026
December 2025
16 Commits • 5 Features
Dec 1, 2025Month: 2025-12 summary for lowRISC/opentitan focusing on ROM security validation, debugger reliability, and CI-friendly testing. Key accomplishments include: (1) ROM_EXT security testing framework and ROM_EXT secure boot validation, with rollback/version checks, fault-injection readiness, new test targets, GDB tracing, and test harness enhancements (plus ROM footprint optimization by disabling compiler jump guards). (2) OpenOCD/Debugger reliability improvements: corrected end-byte handling, ability to halt the CPU during reset, and improved labels/data reading. (3) FiSim and GDB testing improvements: unit tests for FiSim and updated logging for CI. (4) Cryptography alerting and robustness: added cryptolib alert outputs and wrapper-based alert handling to ensure alerts surface in tests. (5) Target and assembly reliability improvements: higher pacing to reduce flakiness and added clobbered registers.
December 2025
16 Commits • 5 Features
Dec 1, 2025Month: 2025-12 summary for lowRISC/opentitan focusing on ROM security validation, debugger reliability, and CI-friendly testing. Key accomplishments include: (1) ROM_EXT security testing framework and ROM_EXT secure boot validation, with rollback/version checks, fault-injection readiness, new test targets, GDB tracing, and test harness enhancements (plus ROM footprint optimization by disabling compiler jump guards). (2) OpenOCD/Debugger reliability improvements: corrected end-byte handling, ability to halt the CPU during reset, and improved labels/data reading. (3) FiSim and GDB testing improvements: unit tests for FiSim and updated logging for CI. (4) Cryptography alerting and robustness: added cryptolib alert outputs and wrapper-based alert handling to ensure alerts surface in tests. (5) Target and assembly reliability improvements: higher pacing to reduce flakiness and added clobbered registers.
November 2025
24 Commits • 6 Features
Nov 1, 2025Month: 2025-11 Concise monthly summary focusing on business value and technical achievements for lowRISC/opentitan.
24 Commits • 6 Features
Nov 1, 2025Month: 2025-11 Concise monthly summary focusing on business value and technical achievements for lowRISC/opentitan.
November 2025
October 2025
1 Commits • 1 Features
Oct 1, 2025Monthly summary for 2025-10: Delivered targeted CW340 FPGA penetration-testing enhancements in opentitan, enabling GDB-based testing of the CW340 RMA lifecycle. Implemented a new pentest target (fpga_cw340_rom_ext) and updated the build/configuration to register and expose it within the existing test harness. This expands hardware test coverage, shortens validation cycles, and improves early detection of regressions in FPGA firmware/RTL interactions.
October 2025
1 Commits • 1 Features
Oct 1, 2025Monthly summary for 2025-10: Delivered targeted CW340 FPGA penetration-testing enhancements in opentitan, enabling GDB-based testing of the CW340 RMA lifecycle. Implemented a new pentest target (fpga_cw340_rom_ext) and updated the build/configuration to register and expose it within the existing test harness. This expands hardware test coverage, shortens validation cycles, and improves early detection of regressions in FPGA firmware/RTL interactions.
September 2025
16 Commits • 2 Features
Sep 1, 2025September 2025 (2025-09) achievements in lowRISC/opentitan focused on security hardening, testability, and reliability. Delivered a Python-based penetration testing framework with cryptolib test integration, expanded test scripts/build targets, and improved testing infrastructure; implemented comprehensive cryptographic library hardening to mitigate side-channel and fault attacks, including hardened macros, launder functions, and checksum verifications. Fixed a critical alert handling bug in penetration testing firmware to ensure alerts remain properly unconfigured when disabled. These efforts collectively reduce risk in security-critical firmware, accelerate validation cycles, and demonstrate strong cross-disciplinary skills in software, cryptography, hardware-test tooling, and CI workflows.
16 Commits • 2 Features
Sep 1, 2025September 2025 (2025-09) achievements in lowRISC/opentitan focused on security hardening, testability, and reliability. Delivered a Python-based penetration testing framework with cryptolib test integration, expanded test scripts/build targets, and improved testing infrastructure; implemented comprehensive cryptographic library hardening to mitigate side-channel and fault attacks, including hardened macros, launder functions, and checksum verifications. Fixed a critical alert handling bug in penetration testing firmware to ensure alerts remain properly unconfigured when disabled. These efforts collectively reduce risk in security-critical firmware, accelerate validation cycles, and demonstrate strong cross-disciplinary skills in software, cryptography, hardware-test tooling, and CI workflows.
September 2025
August 2025
4 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — LowRISC/opentitan: Delivered consolidated Penetration Testing Enhancements across hardware alerts, crypto tests, FPGA compatibility, and test reliability. Implemented configurable AES test inputs in crypto_fi, adjusted pentest init to disable flash fatal alerts for FPGA compatibility, and aligned random value generation in Ibex SCA tests to improve reliability and comparability. These changes broaden security coverage, improve test reliability across platforms, and accelerate cross-hardware validation, supporting higher confidence in hardware/firmware security before release.
August 2025
4 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — LowRISC/opentitan: Delivered consolidated Penetration Testing Enhancements across hardware alerts, crypto tests, FPGA compatibility, and test reliability. Implemented configurable AES test inputs in crypto_fi, adjusted pentest init to disable flash fatal alerts for FPGA compatibility, and aligned random value generation in Ibex SCA tests to improve reliability and comparability. These changes broaden security coverage, improve test reliability across platforms, and accelerate cross-hardware validation, supporting higher confidence in hardware/firmware security before release.
July 2025
29 Commits • 19 Features
Jul 1, 2025July 2025 monthly summary for lowRISC/opentitan focused on delivering cryptographic capability, expanding test coverage, and strengthening CI/build integrity, while improving test determinism and resilience. Key work spanned feature scaffolding, broader cryptographic targets, test instrumentation, and observability enhancements that collectively increase security, reliability, and engineering velocity.
29 Commits • 19 Features
Jul 1, 2025July 2025 monthly summary for lowRISC/opentitan focused on delivering cryptographic capability, expanding test coverage, and strengthening CI/build integrity, while improving test determinism and resilience. Key work spanned feature scaffolding, broader cryptographic targets, test instrumentation, and observability enhancements that collectively increase security, reliability, and engineering velocity.
July 2025
June 2025
5 Commits • 2 Features
Jun 1, 2025June 2025 (2025-06) monthly summary for lowRISC/opentitan: Key features delivered include Sensor Control and Alert Integration in the Pentest Framework and Cryptographic Test Framework Enhancements with modularization and FvsR testing. No explicit critical bugs fixed this month; focus was on architecture, test coverage, and framework improvements that enable scalable security validation. Overall impact: broadened test coverage, reduced risk in sensor/alert handling, and established a scalable cryptographic testing foundation across multiple curves.
June 2025
5 Commits • 2 Features
Jun 1, 2025June 2025 (2025-06) monthly summary for lowRISC/opentitan: Key features delivered include Sensor Control and Alert Integration in the Pentest Framework and Cryptographic Test Framework Enhancements with modularization and FvsR testing. No explicit critical bugs fixed this month; focus was on architecture, test coverage, and framework improvements that enable scalable security validation. Overall impact: broadened test coverage, reduced risk in sensor/alert handling, and established a scalable cryptographic testing foundation across multiple curves.
May 2025
5 Commits • 1 Features
May 1, 2025Concise monthly summary for 2025-05 focusing on key accomplishments, major bugs fixed, and business value for lowRISC/opentitan. Delivered enhancements to the Penetration Testing Framework and a critical firmware test bug fix, resulting in stronger security validation and faster feedback loops.
5 Commits • 1 Features
May 1, 2025Concise monthly summary for 2025-05 focusing on key accomplishments, major bugs fixed, and business value for lowRISC/opentitan. Delivered enhancements to the Penetration Testing Framework and a critical firmware test bug fix, resulting in stronger security validation and faster feedback loops.
May 2025
April 2025
1 Commits • 1 Features
Apr 1, 2025April 2025 monthly summary for lowRISC/opentitan. Focused on enhancing ROM_EXT signature verification to strengthen boot-time security and reliability, with minimal impact to release cadence.
April 2025
1 Commits • 1 Features
Apr 1, 2025April 2025 monthly summary for lowRISC/opentitan. Focused on enhancing ROM_EXT signature verification to strengthen boot-time security and reliability, with minimal impact to release cadence.
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Quality Metrics
Correctness93.6%
Maintainability86.4%
Architecture89.4%
Performance83.8%
AI Usage22.8%
Skills & Technologies
Programming Languages
AssemblyBUILDBazelCC++JSONMarkdownPythonRustStarlark
Technical Skills
API DevelopmentAssembly LanguageAssembly Language OptimizationAssembly Language ProgrammingAssembly programmingBazelBazel build systemBug FixingBuild System ConfigurationBuild SystemsC ProgrammingC programmingC++ programmingCI integrationCI/CD
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