AI Summarized Hacker News

Front-page articles summarized hourly.

Android NAT-T keepalive offload bypasses VPN lockdown

Android NAT-T Keepalive Offload Bypass shows that on Android 12+ a normal app can trigger NAT-T keepalives via public IpSecManager/UdpEncapsulationSocket, causing UDP/4500 traffic to exit the VPN despite Always-on VPN and Block connections without VPN. Tests confirm public-path admission and router-directed keepalives exposing the device’s non-VPN IP and timing. Root cause: collapsed trust and abandoned resource validation in startNattKeepaliveWithFd, merging privileged raw-fd and public paths. Device-class exposure affects most Android 12+ devices (~91%). Mitigations: enforce VPN-admission before offload, separate fd/resource checks, deprecate normal-app IPsec, and require fail-closed offload; regression tests advised.

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How we manage and engage with our horses shapes their personality

A University of Turku study finds horse personality is shaped by housing, riding, care, and owner–horse relationships, not just genetics. Analyzing 2,257 owners and 2,767 horses, they identified four dimensions: Human Sociability, Attentiveness, Neuroticism, and Horse Sociability. Intrinsic factors (age, breed) matter (e.g., Warmbloods higher Neuroticism; geldings more sociable and attentive). Long-term relationships and regular riding (4–7×/week) linked to more sociable, attentive, calmer horses; solitary housing reduced Horse Sociability. Cross-sectional; causality not proven. Published in Royal Society Open Science.

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I made a build profiler to understand Bun's compile times

Buildprof is an open-source Linux build profiler that records all processes and I/O to render a cross-tool build timeline, revealing bottlenecks. Applied to Bun’s Linux CI, Zig’s Full-LTO linker dominated time; Rust’s multi-crate approach enabled parallelism. Switching Zig to ThinLTO and rebuilding WebKit/ICU cut linking to about 7–8 minutes; the remaining gap stems from Zig’s single-module bottleneck. It also covers implementation (ptrace-based recording, file I/O tracing) and potential improvements.

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How Trail of Bits helps verify the integrity of Signal chats

Trail of Bits explains Automatic Key Verification (AKV), a key-transparency approach that makes a device’s view of phone-number–to–public-key mappings globally consistent. Trail of Bits runs an independent auditor that signs Merkle-tree heads and, with Signal and Cloudflare, ensures clients see the same key lineage. When AKV is enabled, the Signal client fetches heads and requires that each head be endorsed by all auditors within the last seven days; a missing/invalid signature triggers a warning. The auditor is open source; enable AKV in Settings > Privacy > Advanced; fall back to safety-number comparisons if needed.

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LG denies TV spying claims, says tracking and snooping concerns 'not true'

LG has rejected Gamers Nexus’s claim that its smart TVs constantly log, record audio, and upload data for 216 million TVs. LG says voice data is processed only when the remote’s button is pressed or a wake word is detected, with on-device processing and data deleted if not triggered; standby mode listens for the wake word only if Far-Field is enabled. TVs can scan the local network for devices, and ACR is opt-in and not used for advertising without consent. Tom’s Hardware has not independently verified the allegations.

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Is it time for a Luddite Renaissance?

Throughline asks whether a modern “Luddite Renaissance” is warranted by examining the 19th-century Luddite rebellion as a labor movement defending jobs from mechanization. With the rise of AI, some fear existential disruption, and the episode uses a listener question to explore lessons about technology and human agency from Luddites. Guests include Katrina Navickas, history professor and author. The discussion aims to understand how past resistance informs present negotiations with automation.

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I refuse to let SPICE die

vd_agent is a community-maintained fork of the abandoned freedesktop.org SPICE Windows guest agent. It provides a Windows service (spice-agent) that runs vdagent.exe per session, enabling mouse input without pointer grabbing, desktop resolution matching the client, clipboard and file transfer between host and guest, and dynamic resizing. The fork preserves building and shipping for current guests, notably Windows 11 VMs on Linux, and includes a multi-GPU mouse fix. It is GPL-2.0-or-later. The repo has pinned submodules (spice-protocol, spice-common), build scripts (Autotools + MinGW-w64; optional CMake/MSVC), and CI for MSI packaging and signing.

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Europe's "Less" Is Doing More Than Anyone Gives It Credit For

Europe’s “Less” means doing more with less energy. The EU now uses 44% less energy per euro of output than in 1995, with more than a third of that improvement since 2019, while GDP has risen ~70% and emissions are down ~40%. Russian gas fell, replaced by US LNG; renewables surged to a large share of electricity. Yet some energy-intensive plants closed, hurting jobs, and energy costs remain high. Policy responses (AccelerateEU) push electrification and storage; energy communities and cooperatives offer localized, stay-at-home production. Growth remains modest but energy sovereignty grows.

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LG responds to TV spying allegations

LG pushed back at reports that its smart TVs continuously record or upload user audio, saying wake-word detection is processed locally and that ACR, voice recognition, and interest-based advertising are optional and not on by default. Critics (GamersNexus, Level1Techs, and researchers) showed LG TVs log ambient conversations long after listening would have stopped, raising privacy concerns. LG claims ACR uses onboard audio fingerprinting and does not collect screenshots or other recordings, but did not address broader data-collection, sharing, or how privacy options are presented.

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Microcode in Intel's 8087 floating-point chip: the scale instruction

William Shirriff’s blog explains how Intel’s 8087 FPU implements the FSCALE instruction in microcode. FSCALE scales a number by a power of two by adjusting its exponent, but the microcode is highly complex, using over 140 micro-instructions and subroutines. The post describes the 8087’s 80-bit internal temporary-real format, the eight-register stack with tags, and the datapath (shifter, adder, exponent converter). It covers handling of special values (NaN, infinity, denorms), exceptions, and rounding, including denorm creation and the guard/round/sticky bits. It highlights microcode/hardware cooperation and notes reverse-engineering efforts.

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Overshoot: The World Is Hitting Point of No Return on Climate

The world is poised to overshoot the 1.5°C ceiling, with a three-year average ending in 2025 likely above the threshold. Emissions remain high, natural carbon sinks weaken, and warming could accelerate. Tipping points—AMOC collapse, Amazon dieback, Arctic/ice-sheet destabilization—could trigger irreversible changes. Impacts are already rising: heat waves, wildfires, floods, and higher costs. Negative-emission and carbon-capture ideas exist but scale is uncertain; geoengineering (solar shading) is controversial and not a fix. Policy gaps persist; without rapid action, overshoot risks becoming permanent.

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Moby-Dick and the Indefinite Sublime: On facing the white page

Tom McCarthy’s Yale Review essay argues Moby-Dick embodies the Indefinite Sublime: whiteness defies representation, the sea infinity. Drawing on Longinus, Burke, Kant, Lacan, Lyotard, and Freud, it shows Melville rendering knowledge through form, language, and writing itself. The Pequod becomes a workshop of signs and machines—hulls as text, sperm as currency, whale heads as quoin—where pursuit of the white whale exposes reason’s limits and the necessity of signification. It links Paradise of Bachelors and Tartarus of Maids to a drama of failed nuptials, and reads Queequeg’s tattoos and Pip’s madness as keys to art. Moby-Dick is writing about writing.

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Compiler Can Undo Your Security Checks

David Bombal and security researcher Chris Domas explain that secure C code can become vulnerable in the compiled binary because the CPU executes compiler output, not source. Legal optimizations can drop memory-clearing operations, forge timing flaws, and hide protections. The C abstract machine, register pressure, struct layout, and data size can determine whether a binary is safe; tiny changes in size can flip security. Rust isn’t a guaranteed fix, and swapping GCC/Clang isn’t the answer. Developers should enable warnings, use sanitizers, analyze optimized builds, and test the binary shipped; AI has scanned millions of lines to spot risky patterns.

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Performance of WebAssembly Runtimes in 2026

Frank Denis compares libsodium running on WebAssembly runtimes using 2024–2026 builds to see if performance actually improves. Wasmer tops the field; Wasmtime improves steadily; Bun jumps in 2026; WAVM is fastest baseline but hard to compare historically; WasmEdge shines in AOT; Wazero and WAMR are flatter. The biggest gains come from wide_arithmetic; Wasmtime and Wasmer benefit most (Wasmtime: ~2.41x native baseline, ~1.46x with wide_arithmetic; Wasmer: ~2.08x native, ~1.33x with wide_arithmetic). wasm2c stays competitive for ahead-of-time C. Takeaway: with the right runtime and features, WebAssembly can approach native performance for crypto workloads, but results vary by runtime and feature support.

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