Stealing Keys From Hardware Wallets: A Single Trace Side-Channel Attack on Elliptic Curve Scalar Multiplication Without Profiling

Abstract

Over the past decade, decentralized cryptocurrencies have received attention in industry and academia. Hardware wallets are dedicated devices that manage cryptocurrencies safely without entrusting cryptographic keys to a third party. Side-channel attacks have been widely studied in cryptanalysis and have already been proven threatening, but analysis on hardware wallets still needs to be researched. Although the previous work demonstrated several side-channel vulnerabilities, their attacks require a finely controlled environment or a learning phase of target devices' physical properties before the attacks. This paper proposes a side-channel attack on hardware wallets extracting private keys. The proposed attack needs a single power trace measured when wallets process elliptic curve scalar multiplication with private keys. Our attack is reasonable since we do not damage the device under attack and do not target a specific device but an algorithm; it is widely applicable to wallets using that algorithm or analogous ones. It also presents the attack results conducted with three datasets: simulation, ChipWhisperer, and actual dataset collected from the Trezor Model One, the first and representative hardware wallets which comply with the de facto standard of hardware wallets.