We care about how things are made.

Virtualization-based laptop security

A hardened business laptop, presented at HITB+ CyberWeek 2019 in Abu Dhabi. The threat model covers malicious firmware that survives OS reinstalls, attackers with brief physical access and supply-chain implants. A minimal, secure-booted Linux on a read-only partition owns the hardware and runs Windows 10 in an IOMMU-protected hypervisor compartment with direct access to the GPU only. USB ports, cameras, microphones and speakers stay isolated from Windows by the virtualization layer and are only exposed by Linux policy when they are needed, which prevents firmware compromise of these devices and unauthorized audio or video recording. Network traffic is routed by Linux, so it cannot bypass the VPN where the use case requires one. Linux also handles the double disk encryption (TCG Opal and LUKS2 with Argon2 key derivation tied to the TPM and an external USB crypto token), so Windows malware can neither become persistent in firmware nor reach the keys. A decoy password opens a disposable system for border checks; disabled DMA-capable ports, tamper detection and glitter nail polish on the screws complete the picture.

• Talk recording: Securing your laptop like you mean it, HITB+ CyberWeek 2019 (YouTube)

Arm mbed uVisor

A self-contained secure hypervisor for Cortex-M microcontrollers that splits firmware into isolated compartments. It supports both Armv7-M (Cortex-M3, M4 and M7), where it enforces the boundaries with the memory protection unit, and Armv8-M (Cortex-M23 and M33), where it also uses TrustZone. Each compartment owns its memory regions and peripherals through access control lists, and secure gateways let code cross a boundary one function call at a time, so a single driver or crypto routine can run in its own compartment. uVisor became a core component of the Arm mbed operating system.

• Interview: Security for Arm IoT devices
• Slides: Practical real-time operating system security for the masses (Arm TechCon 2016)
• Slides: Resilient IoT security, the end of flat security models (Arm TechCon 2015)

HID iCLASS security research

Reverse-engineered HID's iCLASS access-control readers to recover the Standard Security keys, showing that breaking one reader opens every installation running that mode. Documented in the white paper Heart of Darkness, presented at 27C3 with Henryk Plötz, and continued with Radboud University Nijmegen in the ESORICS 2012 paper Dismantling iClass and iClass Elite.

• White paper: Heart of Darkness (PDF)
• 27C3 talk: HID iClass demystified
• 27C3 slides (PDF)
• Paper: Dismantling iClass and iClass Elite, ESORICS 2012
• Tools and data on GitHub

Blinkenlights Stereoscope

For Nuit Blanche 2008, Project Blinkenlights turned the two towers of Toronto City Hall into a giant display: 960 windows, each lit by a lamp with eight grey levels. The lamps were switched by 2.4 GHz wireless dimmers built on OpenBeacon radio hardware, designed and produced for the installation.

• Documentation video (Vimeo)
• Stereoscope software on GitHub
• Background: Project Blinkenlights on Wikipedia

OpenBeacon readers and enclosures

USB tags for offline operation with an injection-moulded case, a PoE Ethernet reader in a cast aluminium housing and the OpenPCD 2 13.56 MHz reader, all taken through production setup in China.

OpenBeacon proximity tags

Open-source 2.4 GHz active RFID tags that log face-to-face contacts for weeks on a coin cell. First used to track 1,500 visitors at the 2006 Chaos Communication Congress, later in social-network research with SocioPatterns and in museum installations worldwide.

Xbox security analysis and Xbox-Linux

As a founding member of the Xbox-Linux project, helped analyze and break the trusted-computing security of the first Xbox in 2002, ported the first Linux system to the console and built a networked Linux distribution that fit into one megabyte of onboard flash. The work is documented in Andrew Huang's book Hacking the Xbox.

• 19C3 talk: It's my box
• Talk slides (PDF)
• In Hacking the Xbox (No Starch Press, 2003)
• Interview: Telepolis, “Ganz neue Spielchen” (German)
• Interview: golem.de (German)
• Interview: taz, “Deine Spielkiste gehört dir” (German)
• Background: Xbox Linux on Wikipedia

Arm Trusted Firmware-M explorer

An interactive memory explorer for Arm Trusted Firmware-M, the open-source PSA reference firmware for Cortex-M. It shows the code size and memory consumption of a TF-M build as a zoomable sunburst, from the MCUboot BL2 bootloader to the complete TrustZone-M layout of an RTX application across the secure and non-secure worlds, on the CoreLink SSE-200 subsystem (MPS2+, AN521). The size-optimized builds behind it are produced automatically in Docker on CircleCI.

• Build environment on GitHub (Docker, CircleCI)