~/blog / wi-fi
Wi-Fi
9 posts tagged Wi-Fi.
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Zephelin on an nRF54L: A 5× WPA3 Slowdown, Four Bugs, and What Profiling Costs Antmicro's Zephelin profiler hit 1.0 last month. We put it on an nRF54LM20 DK running upstream Zephyr and pointed it at real problems: a WPA3-SAE commit that takes 3.3 seconds on Zephyr v4.4.1 and 650 ms with one Kconfig default restored, a stack sized 4× too large, and the question of what observing all this costs. Getting call graphs at all took four fixes, now upstream as PRs. -
Constant-time isn't enough: why WPA3-SAE had to abandon Hunting-and-Pecking for Hash-to-Element WPA3-SAE turns your password into an elliptic-curve point, and the old Hunting-and-Pecking method leaked it through timing. Padding the loop didn't fix it — and neither does SSWU alone. A deep look at constant-time crypto as a property of the silicon: why the leak channel changes across Cortex-M, Cortex-A and x86, why DIT/DOITM and your compiler matter, and how you'd actually measure it. -
Three Ways to Fake Wi-Fi, One Merged: Zephyr's New hwsim Linux has had mac80211_hwsim for years; Zephyr had nothing like it — you couldn't test the Wi-Fi supplicant without a radio on the bench. Three different fixes landed on the table at once; an RFC and a Wi-Fi telco sorted out which does what, and I built and merged the in-process one: N virtual radios in a single image, running real WPA2 and WPA3 handshakes with zero hardware. Here's the design call, the one problem that makes it hard on Zephyr specifically, and the war story of getting SAE green. -
Same Bug, Two Models: One Wasted a Day, One Found the Silicon Limit Two real nRF Wi-Fi bugs debugged with AI agents. On the same bug, a cheap model burned a day on confident fiction while a frontier model found a hardware limit in minutes — and a fix that passed on the board was still wrong. A field report on model choice, the symptom lying about its layer, and the instruments — sniffer, profiler, bisect — that actually settle it. -
Wi-Fi Crypto Can't Go Fully PSA: Inside the Mbed TLS 4.x Migration Wi-Fi security can never be fully PSA-compliant — the standards mandate legacy algorithms PSA won't touch. Here's what porting hostap's crypto to Mbed TLS 4.x and PSA actually took: a deleted DH module, dropped curves, deliberate hacks, and a detour through the bootloader — all riding into nRF Connect SDK 3.4.0 LTS. -
From EWDK Build to Bidirectional Ping: Debugging Windows' New WiFiCx Sample Driver In 2024 I filed a GitHub issue asking Microsoft for a WiFiCx reference driver. It closed this year, pointing at a brand-new sample that didn't actually pass traffic. Here's the pktmon trace that found the missing access point, and the PR that fixed it. -
Humans in Wi-Fi: Chaitanya Tata on Wi-Fi Sensing and 802.11bf Dotstar Systems founder Chaitanya Tata joins Wi-Fi Nomads' "Humans in Wi-Fi" at the Wi-Fi Knowledge Summit 2026 to talk Wi-Fi Sensing and 802.11bf. -
Wi-Fi Turns 27 — And It's Never Been More Essential June 20 is World Wi-Fi Day, and the technology under almost every digital moment of modern life turns 27. From black-hole astronomy to mission-critical infrastructure — and why Wi-Fi 8 trades "how fast" for "how certain." -
Your Wi-Fi WPA3 network has a quantum problem. Here's the fix coming in IEEE 802.11bt. WPA3's SAE handshake rests on elliptic-curve cryptography that Shor's algorithm breaks retroactively. A look at the Harvest-Now-Decrypt-Later threat, why MLWE is quantum-resistant, and what IEEE 802.11bt actually defines.