--- title: "Trezor Evaluates Post-Quantum Signature Trade-Offs for Bitcoin Hardware Wallets" description: "CTO Tomáš Sušánka said Trezor may default to larger stateless signatures under the proposed SHRINCS scheme to prevent key reuse vulnerabilities." url: https://basisdesk.news/news/trezor-quantum-resistance-shrincs-bitcoin-wallets published: 2026-11-12T20:41:24.277Z modified: 2026-11-12T20:41:24.277Z section: Tech & Protocols author: Basis Desk Newsroom (AI-generated, source-verified) sentiment: neutral tickers: [BTC] tags: [bitcoin, trezor, quantum-computing, cryptography, hardware-wallets] license: Quote with attribution to Basis Desk (basisdesk.news). Not financial advice. --- # Trezor Evaluates Post-Quantum Signature Trade-Offs for Bitcoin Hardware Wallets CTO Tomáš Sušánka said Trezor may default to larger stateless signatures under the proposed SHRINCS scheme to prevent key reuse vulnerabilities. ## At a glance - **What happened:** Trezor CTO Tomáš Sušánka stated the wallet maker may default to larger stateless signatures under the SHRINCS proposal to avoid key-reuse fund theft. - **Why it matters:** Stateful post-quantum signatures are ten times smaller but risk total fund loss if reused across devices sharing the same recovery seed. - **Who is affected:** Bitcoin hardware wallet developers and self-custody users preparing for post-quantum migrations. - **What's next:** No next step announced. - **Primary source:** [Why the Path to Quantum Resistance Runs Uphill for Bitcoin Wallet Makers](https://decrypt.co/383201/why-path-quantum-resistance-runs-uphill-bitcoin-wallet) — decrypt.co ## Key points - Trezor is considering defaulting to larger stateless signatures to protect users from state-tracking errors under the proposed SHRINCS scheme. - Stateful SHRINCS signatures are ten times smaller but expose funds to theft if one-time signing budgets are accidentally exceeded. - Trezor Safe 7 includes post-quantum authentication for firmware, but full on-chain security requires a network-wide Bitcoin upgrade. ## Editorial remark - **Context:** SHRINCS, introduced by Blockstream researchers as a SHA-256 hash-based scheme, emerged as a leading candidate for post-quantum Bitcoin signatures, forcing wallet developers to balance signature size with key reuse risks. - **Impact:** Hardware wallet manufacturers and end users face trade-offs between higher transaction fees for safer stateless signatures or potential fund loss from state synchronization failures across mirrored devices. - **Watch:** Bitcoin Core developer consensus on post-quantum signature proposals and firmware updates across competing hardware wallet providers. Hardware wallet manufacturer Trezor is preparing for user-experience and security challenges tied to a future quantum-resistant $BTC network, according to an interview with Chief Technology Officer Tomáš Sušánka [1]. The discussion centers on SHRINCS, a candidate post-quantum signature scheme proposed by Blockstream Research Director Jonas Nick and cryptographer Mikhail Kudinov [1]. At the time of writing, Bitcoin traded at $71,361, down 4.2% over 24 hours. SHRINCS employs a composite hash-based framework that gives users a choice between stateful and stateless signatures [1]. Stateful signatures are roughly ten times smaller than stateless alternatives, offering substantial fee and speed advantages, but require strict tracking of remaining signing budgets [1]. Reusing one-time keys beyond this limit leaks cryptographic data, allowing attackers to forge signatures and steal funds [1]. Conversely, stateless signatures avoid state-tracking failure modes but carry significantly larger transaction sizes, creating higher network fee burdens [1]. ## Hardware Bottlenecks and Migration Realities To shield everyday users from catastrophic state-tracking mistakes, Trezor is evaluating an interface model that defaults to larger stateless signatures while relegating stateful options to advanced settings [1]. Sušánka highlighted the operational friction of stateful keys, particularly in common multi-device setups where two hardware wallets share the same recovery seed without a shared state synchronization channel [1]. Broader migration debates have also surfaced in related network initiatives, such as [Bitcoin Developers Propose BIP 360 to Mitigate Long-Exposure Quantum Vulnerabilities](https://basisdesk.news/news/bitcoin-developers-propose-bip-360-quantum-resistance). Beyond transaction-level cryptography, Sušánka noted that hardware signing devices themselves rely on traditional cryptography vulnerable to quantum attacks for internal firmware validation and device authentication [1]. Trezor has begun addressing this vulnerability at the physical layer by deploying models like the Trezor Safe 7, which incorporates post-quantum cryptographic primitives for internal authentication [1]. However, on-chain transactions generated through such hardware will only gain quantum resistance once the broader Bitcoin protocol activates a compatible post-quantum signature upgrade [1]. ## Sources 1. [Why the Path to Quantum Resistance Runs Uphill for Bitcoin Wallet Makers](https://decrypt.co/383201/why-path-quantum-resistance-runs-uphill-bitcoin-wallet) — decrypt.co, 2026-11-12 --- Basis Desk Newsroom · AI-generated, source-verified · https://basisdesk.news/about/how-we-use-ai