Session
Fahrplan - Hauptprogramm 36C3
Hardware & Making

Open Source is Insufficient to Solve Trust Problems in Hardware

How Betrusted Aims to Close the Hardware TOCTOU Gap
While open source is necessary for trustable hardware, it is far from sufficient. This is because “hashing” hardware – verifying its construction down to the transistor level – is typically a destructive process, so trust in hardware is a massive time-of-check/time-of-use (TOCTOU) problem. This talk helps us understand the nature of the TOCTOU problem by providing a brief overview of the supply chain security problem and various classes of hardware implants. We then shift gears to talk about ways to potentially close the TOCTOU gap, concluding with a curated set of verifiable components that we are sharing as an open source mobile communications platform – a kind of combination hardware and software distribution – that we hope can be useful for developing and deploying all manner of open platforms that require a higher level of trust and security.

The inconvenient truth is that open source hardware is precisely as trustworthy as closed source hardware. The availability of design source only enables us to agree that the designer’s intent can be trusted and is likely correct, but there is no essential link between the hardware design source and the piece of hardware on your desk. Thus while open source is necessary for trustable hardware, it is far from sufficient. This is quite opposite from the case of open source software thanks to projects like Reproducible Builds, where binaries can be loaded in-memory and cryptographically verified and independently reproduced to ensure a match to the complete and corresponding source of a particular build prior to execution, thus establishing a robust link between the executable and the source.

Unfortunately, “hashing” hardware – verifying its construction down to the transistor level – is typically a destructive process, so trust in hardware is a massive time-of-check/time-of-use (TOCTOU) problem. Even if you thoroughly inspect the design source, the factory could modify the design. Even if you audit the factory, the courier delivering the hardware to your desk could insert an implant. Even if you carried the hardware from the factory to your desk, an “evil maid” could modify your machine. This creates an existential crisis for trust – how can we know our secrets are safe if the very hardware we use to compute them could be readily tainted?

This talk addresses the elephant in the room by helping us understand the nature of the TOCTOU problem by providing a brief overview of the supply chain security problem and various classes of hardware implants. We then shift gears to talk about ways to potentially close the TOCTOU gap. When thinking about hardening a system against supply chain attacks, every component – from the CPU to the keyboard to the LCD – must be considered in order to defend against implanted screen grabbers and key loggers. At every level, a trade-off exists between complexity and the feasibility of non-destructive end-user verification with minimal tooling: a system simple enough to be readily verified will not have the equivalent compute power or features of a smartphone.

However, we believe that a verifiable system should have adequate performance for a select range of tasks that include text chats, cryptocurrency wallets, and voice calls. Certain high-risk individuals such as politicians, journalists, executives, whistleblowers, and activists may be willing to use a device that forgoes bells and whistles in exchange for privacy and security. With this in mind, the Betrusted project brings together a curated set of verifiable components as an open source mobile communications platform - a combination open source hardware and software distribution. We are sharing Betrusted with the community in the hopes that others may adopt it as a reference design for developing and deploying all manner of open platforms that require a higher level of trust and security.

Additional information

Type lecture
Language English

More sessions

12/27/19
Hardware & Making
Matt Evans
Dijkstra
This talk will cover everything about the Acorn Archimedes, a British computer first released in 1987 and (slightly) famous for being the genesis of the original ARM processor.
12/27/19
Hardware & Making
Sebastian Staacks
Eliza
Modern smartphones offer a whole range of sensors like magnetometers, accelerometers or gyroscopes. The open source app "phyphox", developed at the RWTH Aachen University, repurposes these sensors as measuring instruments in physics education.
12/27/19
Hardware & Making
chipforge
Eliza
(en) We make Standard Cells for LibreSilicon available, which are open source and feasible. And we like to talk and demonstrate what we are doing. (de) Wir machen Standardzellen für LibreSilicon verfügbar, welche Open Source und nutzbar sind. Wir möchten darüber sprechen und vorführen, was wir tun.
12/27/19
Hardware & Making
Phil
Dijkstra
Es soll grundlegend erklärt werden, nach welchen Kriterien Medizinprodukte entwickelt werden. Dazu werden die wichtigsten Regularien (Gesetze, Normen, ...) vorgestellt die von den Medizinprodukteherstellern eingehalten werden müssen. Diese regeln, was die Hersteller umsetzen müssen (und was nicht). Hier wird auch die Frage beantwortet, warum beispielsweise die Apple-Watch (oder genauer gesagt nur zwei Apps) ein Medizinprodukt sind aber die card10 nicht.
12/27/19
Hardware & Making
LaForge
Ada
Billions of subscribers use SIM cards in their phones. Yet, outside a relatively small circle, information about SIM card technology is not widely known. This talk aims to be an in-depth technical overview.
12/28/19
Hardware & Making
Clarke
There's a variety of places - on Earth and beyond - that pose challenging conditions to the ever-shrinking digital circuits of today. Making those tiny transistors work reliably when bombarded with charged particles in the vacuum of space, in the underground tunnels of CERN or in your local hospital's X-ray machine is not an easy feat. This talk is going to shed some light on what can be done to keep particles from messing up your ones and zeroes, how errors in digital circuits can be detected ...
12/28/19
Hardware & Making
Thomas Roth
Dijkstra
Most modern embedded devices have something to protect: Whether it's cryptographic keys for your bitcoins, the password to your WiFi, or the integrity of the engine-control unit code for your car. To protect these devices, vendors often utilise the latest processors with the newest security features: From read-out protections, crypto storage, secure-boot up to TrustZone-M on the latest ARM processors. In this talk, we break these features: We show how it is possible to bypass the security ...