Hitchhiking into Silicon: True Open-Source Hardware Down to the Transistor

Devcon 8 · 5 Nov 2026 · 5:22

Mark Davis of Crossbar gives an unscripted, slide-free lightning talk on open-source hardware for wallets. Mark describes a joint design with hacker Bunny Huang of a microcontroller and security engine with embedded non-volatile memory on one 22nm chip, packaged silicon-side up so it can be inspected. Crossbar also makes a card platform and a consumer multi-party computation (MPC) wallet. The argument is that wallets are weak on the open, private and secure goals when the chip and secure element are closed, and that AI audits make openness more effective than obscurity.

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From Devcon 8, hosted by Ethereum Foundation.

Transcript

[music] Hi. Yeah, I don't have slides. This is kind of impromptu. So, I'm the CEO of a company called Crossbar. Uh we have a booth up on Lotus 3. Uh Crossbar worked with a company called Bow Chip. Uh some of you may know the the famous hacker Bunny Huang. uh we jointly designed what is the world's first open-source microcontroller plus security engine with embedded nonvolatile memory. So it's a complete microcontroller everything you need to run a wallet system all on a single chip in TSMC 22nmter.

So uh you know people in Ethereum talk about this uh acronym crops uh censorship resistant capture resistant open private secure so on uh this the software stack excels in these prop in these properties but the devices used in wallets whether it's a mobile phone hardware wallet are typically security by obscurity closed source the chip design is not open many wallets say it's an open- source wallet but the chip is not open source The security setup is not open source. The secure element is definitely not open source. So we're making various platforms that can be said to be the first truly open-source hardware uh ever to exist. So we have a

example also we're showing on on Lotus 3. You can stop by. Uh we package this chip with the silicon side up so you can actually uh inspect it yourself and verify that it matches the design the design. So it's not only open source but also inspectable. [snorts] Uh so uh bow chip uh supports chip level customers. Uh crossbar has a card level product. It's a, you know, it's a touchscreen, credit card size, fingerprint, uh, sensor, BLE, NFC, wireless charging, USBC. So, it's a kind of wallet form factor. Uh, we call this platform

Ostros, OS T O. If you look for crossbar and ostros, you'll find it immediately. Uh so it's the world's first truly open- source card from silicon to security setup to the the boot code to the you know firmware all the way to the application level and you can develop applications on this. We're supporting a community of developers on the card and then uh biochip is uh supporting a community of developers more at the chip level if you want to put a chip on board. Uh so uh we also have uh uh are are producing a a consumer MPC wallet uh

using this chip. Uh the the brand is called sovereigny. Uh I feel that Ethereum is is strong mainly because it's uh decentralized, permissionless, trustless. Uh, but we drive inputs into that system from wallets that are none of those things. They're centralized, oligarchcont controlled, closed source. So with our open-source MPC wallet, you can have decentralization in entropy generation, decentralization in the key storage, decentralization in the signature process. So that wallet is called sovereignty. So at a higher level, uh there's there's been a lot

[clears throat] of debate in in uh industry lately about security by obscurity, security by openness. Uh so all of certification is based on security by obscurity. It's required in the certification to be secret. Uh a growing community pe of people is thinking, you know, with AI uh today that really doesn't make sense. AI can reverse engineer and cut through any obscurity. So security by obscurity and secrecy is much less effective for the same reason. Security by openness is suddenly much more effective because the the danger of open source was always you know what if nobody actually looks. Uh

now with AI audits and uh you know visibility into the code is uh much more accessible. So you can do quick uh highquality cheap audits. So open source works better, secrecy works worse. You think AI is very disruptive in the security process. Uh it's also disruptive just in general design. Coding now uh a human coder can't really make use of an open- source chip all that much, but AI coding absolutely can read the entire design of the chip and code very accurately, quickly. Uh so we think AI is disrupting just general microcontroller design flow and you'll

see uh you'll see a prevalence of AI design flow in the future and we're hoping to be at the forefront of that. So thank you. >> [music]