Paper 2026/798 Original: eprint.iacr.org/2026/798 ↗

Implementing CCZ Gates with Variation of Gate Teleportation for Quantum Homomorphic Encryption on NISQ Platform

Abstract

While quantum computing technologies are revolutionising key industries, distributed quantum hard- ware services are dominated by quantum providers such as IBM, Google, and AWS. It raises critical data security concerns across sectors such as banking, defence, and healthcare. To address this issue, Quantum Homomorphic Encryption (QHE) has emerged as a solution that enables computations on encrypted quantum data while preserving privacy. Despite its promise, deploying QHE remains challenging due to circuit complexity and the noise in today’s quantum systems. In this work, we confront these barriers directly by implementing QHE on Noisy Intermediate-scale Quantum (NISQ) devices using the Variation of Gate Teleportation (VGT) scheme. In particular, we focus on implementing the CCZ gate, a key non-Clifford gate that makes a quantum gate set universal when combined with Clifford gates. By leveraging the techniques from the Classical Quantum Circuit (CQC)- QHE framework proposed by Ortega et al. in 2025, our implementation reduces computational cost and improves resource efficiency. As a result, our approach can support 7 qubits and 14 T-gates in the circuit without large errors, improving on existing QHE implementations.