Twining the Threads

Zou Kun, Xinfeng Dong, Zhang Fuzhong +1 more

The result of resource consumption in quantum attack implementation of cryptographic algorithm is an important metric to evaluate the security strength of cryptographic algorithm against quantum attack. This paper studies complete implementation of quantum attack on cryptographic algorithm using Grover meets Simon method. We find 9-round quantum distinguisher whose round is the longest currently about TWINE, and utilize Grover meets Simon method to carry out 14/15-round quantum key recovery attack on TWINE-80/TWINE-128 with lower complexity than exhaust attack. Furthermore, we give complete implementation of quantum oracle and QAA algorithm in TWINE’s quantum key recovery attack for the first time. The circuit is suitable for all implementation of quantum key recovery attack on block cipher using Grover meets Simon method.

Javad Kazemi, Michael Fellner, Riccardo J. Valencia-Tortora +2 more

We present an efficient implementation of the Parity Architecture for neutral-atom quantum processors. We adapt Parity Twine Networks (PTNs) to different atom layouts, native entangling gates, and atom-shuttling capabilities. This provides a general framework for hardware-aware optimization of gate count, circuit depth, and atom transport for quantum circuits encoding arbitrary interaction graphs in a common basis. Specifically, we develop PTN constructions based on different native entangling-gate realizations, namely CZ, CZSWAP, and iSWAP, providing flexibility to accommodate different hardware capabilities on both static and mobile neutral-atom platforms. Using the quantum Fourier transform (QFT) as a representative example, we demonstrate substantial reductions in two-qubit gate count, atom transport, and circuit depth. These resource savings translate into an estimated circuit fidelity three orders of magnitude higher than competing compilation strategies for a 30-qubit QFT. We further extend the construction to the recently introduced optimistic QFT and discuss the broader applicability of PTNs to other quantum algorithms on neutral-atom platforms.

Nabila Abdessaied, Rolf Drechsler

Thomas Grurl, Jürgen Fuß, Robert Wille

J. A. Montañez-Barrera, Yanjun Ji, Michael R. von Spakovsky +2 more

Mapping quantum approximate optimization algorithm (QAOA) circuits with nontrivial connectivity in fixed-layout quantum platforms, such as superconducting quantum processing units (QPUs), requires a transpilation process to match the circuit to the hardware layout. This step is critical for reducing error rates on noisy QPUs. Two approaches that improve the resources required for such transpilation are the SWAP network and parity twine chains (PTC), which reduce the two-qubit gate count and circuit depth needed to represent fully connected circuits. In this work, we introduce a simulated annealing-based method that further reduces the encoding overhead of PTC and SWAP networks for QAOA circuits with nonfully connected two-qubit interactions. The method is benchmarked against various transpilers, including the Qiskit SAT mapper, demonstrating that beyond specific connectivity thresholds it achieves significant reductions in both two-qubit gate count and circuit depth. For example, for a 120-qubit QAOA instance with 25% connectivity, our method achieves an 87% reduction in depth and a 29% reduction in two-qubit gates compared with the Qiskit transpiler. Finally, the practical impact of PTC encoding is validated by benchmarking QAOA on the and devices, showing improved performance for systems of up to 20 qubits.

Stefan Hillmich, Robert Wille