I build the defensive tooling analysts actually use, and I'm aiming it at federal cyber operations — taking cybercrime off the board.
Current research
CVE Replay · Study and results
Independent offline reproduction of the published CVE-2026-44431 redirect-header issue, originally reported by christos-cantina-security. The harness compares urllib3 2.6.3 and 2.7.0. On 27 September 2026, all 12 expected outcomes matched: six cases per release, including the affected behavior and benign controls. Inspect the passing regression workflow.
Call Boundary · Experiment and test record
A local authorization gate that binds a signed approval to one actor, audience, tool, target, complete arguments, time window, and nonce. The 27 September 2026 run passed 56 tests and 29 controlled vectors, including replay across processes and restarts. Python, HMAC-SHA256, and SQLite. Inspect the passing regression workflow.
Binary Boundary · Native and decompiler study
An original C fixture comparing Boolean decoding and unsigned range checks across O0 and O2 builds. Native execution and Ghidra exports expose where recovered types differ from the source contract. A fresh 27 September 2026 rerun matched the recorded native results and decompiler output. It covers every byte value and 21,728 range inputs per build; the full 32-bit input space is not exhausted.
Proposed work — Filament PR #1
Signing checks tied to the selected app, identity, and connected device. The open pull request invalidates approval when an input changes and discards stale responses. Portable CI passed on 12 September.
Earlier projects — Tools · DetectLab · PolicyScout / ArmSky
Credentials — Cisco Certified in Cybersecurity · (ISC)² Candidate · Blue Team Junior Analyst · 18 Anthropic AI certificates
Working with — Python · FastAPI · scikit-learn · Docker · Cloudflare · Neo4j · Elasticsearch · the MITRE ATT&CK framework
How I work — controlled reproductions, inspectable test records, and explicit limits on what the evidence establishes.
Hudson Valley / NYC metro · federal cyber operations · sergio.w.rdz@gmail.com · sergrdz.pages.dev