Bas Westerbaan
Principal Research Engineer at Cloudflare
Nijmegen, Gelderland, Netherlands
Summary
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Rockstar🎓
Top SchoolBas Westerbaan is a Principal Research Engineer with 16 years of experience specializing in cryptography and post-quantum security, currently leading research efforts at Cloudflare from Nijmegen. He holds a PhD in Mathematics from Radboud University and has a track record spanning academia and industry, including roles at PQShield, UCL, and multiple research fellowships. Bas is an active open-source contributor—notably to Cloudflare’s CIRCL cryptographic library—where he optimized SHA-3/SHAKE implementations, reduced heap allocations, and refactored AVX2 code to prepare for post-quantum primitives like CRYSTALS-Dilithium. He also implemented hybrid post-quantum key exchange in cloudflared and adapted TLS 1.3 handshakes, bridging cutting-edge research with production-grade security. Known for practical low-level optimizations and protocol work, he combines rigorous mathematical training with systems-level engineering to make post-quantum cryptography deployable at internet scale.
16 years of coding experience
7 years of employment as a software developer
Doctor of Philosophy - PhD Mathematics, Doctor of Philosophy - PhD Mathematics at Radboud University
Stackoverflow
187reputation
2kreached
3answers
1question
Github Skills (18)
tls1210
tls1310
post-quantum-cryptography10
mtls10
go10
cryptography10
libtls10
reverse-proxy9
go-modules9
avx9
golang9
equation6
latex6
linux6
python6
Programming languages (18)
Github contributions (5)
cloudflare/circl
Feb 2020 - Dec 2022
CIRCL: Cloudflare Interoperable Reusable Cryptographic Library
Role in this project:
Back-end Developer
Back-end DeveloperContributions:266 reviews, 78 commits, 106 PRs in 2 years 10 months
Contributions summary:Bas primarily contributed to the cryptographic library, `cloudflare/circl`, with a focus on SHA-3 and SHAKE implementations to support CRYSTALS-Dilithium. Their work involved optimizing code by reducing memory allocations and preventing heap escapes, and adding support for SHAKE-256. They refactored AVX2 code and enhanced the existing code base by improving the memory alignment in preparation for future features.
ecdhsikecryptographicgoed25519
cloudflare/cloudflared
Aug 2022 - Jan 2023
Cloudflare Tunnel client (formerly Argo Tunnel)
Role in this project:Back-end Developer & Security Engineer
Back-end Developer & Security EngineerContributions:4 commits, 2 PRs, 7 comments in 4 months
Contributions summary:Bas contributed to the implementation of post-quantum hybrid key exchange functionality, indicating a focus on cryptographic security. They updated the `qtls` library and modified handshake processes for TLS 1.3, enhancing the security and potentially improving performance. Further work involved adding a post-quantum flag to the quick tunnel, suggesting work on a secure communication channel. The user also updated dependencies and updated the go.mod file.
argo-tunnelproxycloudflarecloudflare-tunnelzero-trust-network-access
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