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IEEE Dallas Circuits and Systems Conference (DCAS)

Security Evaluation of Approximate Quantum Adders

Bhaskar Gaur, Himanshu Thapliyal

Published Apr 10, 2026• 1 citation
Publisher

Abstract

Quantum addition is a vital building block for many quantum applications, yet exact adder architectures exhibit long carry paths and higher depth, increasing their exposure to quantum attacks. This paper presents a security driven evaluation of quantum approximate adders with carryout, having constant depth approximation and benchmarks them against two exact quantum adders. We evaluate resilience against four attack models: (1) Stuck-at$\vert 0\rangle /\vert 1\rangle$qubit attack, (2) State preparation attack, (3) Gate attack, and (4) Crosstalk attack in multi-tenant scenario. We use an emulator provided by Quantinuum that models its H1 ion trap-based 20-qubit quantum computer to conduct attacks. Our results indicate that approximate adders show higher resilience to noise, state preparation, gate, and crosstalk attacks, with AQA3 outperforming AQA4, which outperforms AQA5, due to increasing gate counts across zero, single CNOT layer, and one Toffoli gate respectively. Exact adders remain more robust against stuck-at$\vert 0\rangle /\vert 1\rangle$qubit attacks, as their carry propagation structure acts as an error absorbing mechanism, highlighting a security accuracy trade off for selecting adders in error-tolerant quantum applications.

DOI
10.1109/dcas69364.2026.11544772

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