Thread by @P3b7_

At @Ledger, you might know that we have the @DonjonLedger, our dedicated team constantly conducting open security research.

We recently worked with Trezor, revealing that their Trezor Safe 3 was susceptible to physical supply chain attacks. Here's a thread on our findings:🧵

Our Ledger Donjon security research revealed that if a Trezor Safe3 device was stolen, an attacker could theoretically tamper with the device and modify the software running on it, endangering its user’s funds, even if this device uses a Secure Element.

Secure Elements - a technology Ledger has pioneered for securing digital assets - are chips specifically designed to withstand physical attacks, providing a robust safeguard for users' secrets. Trezor's new Safe line of products incorporates this technology, marking a substantial security improvement.

The Trezor Safe 3 and Safe 5 devices feature a two-chip design: a Secure Element paired with a microcontroller. The Secure Element protects the user's PIN and cryptographic secrets, effectively thwarting inexpensive hardware attacks like voltage glitching.

The Secure Element used in Trezor Safe devices is the Optiga Trust M by Infineon. It ensures that users' secrets remain secure even if the device is misplaced or stolen. This represents a significant advancement in security.

However, our Ledger Donjon security research found that cryptographic operations are still performed on the microcontroller, which can be vulnerable to more advanced attacks. If an attacker modifies the software on the microcontroller, they could potentially access the user's funds remotely.

Trezor has implemented additional layers of protection, such as a firmware integrity check, to detect modified software. While this mechanism is clever, it can be bypassed by determined attackers. Ledger Donjon was able to demonstrate this in our finding and subsequent reporting to Trezor.

At Ledger Donjon, our mission is to push the boundaries of security for the benefit of the whole crypto ecosystem. We will continue to research and collaborate to protect users under all relevant threat models. The collaboration with Trezor exemplifies this commitment.

We appreciate Trezor’s responsiveness to this responsible security disclosure, and that Trezor addressed the vulnerabilities we found, showcasing the importance of continuous improvement and cooperation in the crypto space.

We believe that making the ecosystem more secure helps everyone, and is critical as we push towards broader adoption of crypto and digital assets.

Read the full analysis from the Ledger Donjon, and follow to stay tuned for more updates as we continue to innovate and enhance security in the crypto world. ledger.com/why-secure-ele…