Single flux quantum (SFQ) technology is currently used as a cryogenic control and readout circuitry of superconducting quantum computers. The low power operation and high switching frequency of SFQ technology… Click to show full abstract
Single flux quantum (SFQ) technology is currently used as a cryogenic control and readout circuitry of superconducting quantum computers. The low power operation and high switching frequency of SFQ technology are instrumental to efficiently scale a quantum computer. With the growing interest in the hardware security of SFQ circuits, a novel side-channel leakage mechanism in SFQ-to-dc converters is uncovered in this article. The leakage mechanism is investigated for two logic styles, namely, rapid SFQ (RSFQ) and energy-efficient RSFQ (ERSFQ). By observing the fluctuations in the power supply provided by the room temperature electronics, a malicious adversary can extract critical information about the applied input signals. This type of side-channel leakage can lead to serious security vulnerabilities for superconducting electronics and quantum computers. Two potential side-channel attacks that exploit this vulnerability and target SFQ-based qubit control and readout systems are proposed.
               
Click one of the above tabs to view related content.