Hardware Ready Ready to Bench?
Tomáš Sušánka, CTO of Trezor, outlined in an interview released in November 2026 the technical complexities associated with implementing the post-quantum signature scheme SHRINCS on hardware wallets. The discussion focuses on the compromises necessary to protect funds from attacks by future quantum computers, highlighting how the transition is not free of significant obstacles for manufacturers and users.
Why it matters
Quantum resistance is a central theme for the long-term security of the Bitcoin network. SHRINCS is considered the leading candidate in the community, but presents a critical distinction between stateful and stateless signatures. The former are more efficient in terms of size, being approximately 10 times smaller than other options, but require rigorous management of the device’s internal state. As highlighted by Sušánka, accidental reuse of keys in stateful signatures can lead to signature forgery and theft of funds. For this reason, Trezor is evaluating making stateless signatures the default setting. The latter are safe to reuse but result in larger sizes and slower speeds, with possible repercussions on transaction fees and processing speed. The CTO clarified that state management should not fall on the end user, but be securely managed by manufacturers.
The numbers
Stateful signatures in the SHRINCS scheme are approximately 10 times smaller than stateless alternatives. No further specific numerical data is available regarding costs or exact transaction sizes in the current context, but the size difference is the main technical factor cited by sources.
What remains to be understood
It has not yet been confirmed whether Bitcoin will officially adopt the SHRINCS scheme nor when any potential network upgrade to post-quantum security will occur. Furthermore, the possibility of sharing state between two devices using the same recovery seed remains an unresolved technical challenge, a problem highlighted by Sušánka. Current hardware devices, including new models like the Trezor Safe 7, already support some post-quantum cryptography functions for firmware authentication, but will require physical updates to cover all remaining vulnerabilities.
This article is for informational purposes only and does not constitute financial advice or an investment recommendation.
* Content created with the assistance of artificial intelligence systems.