New protocol cuts quantum hardware needs for secure computing

Researchers at Quandela, a company based in Massy, France, have developed a new protocol that drastically reduces the technological demands on both clients and servers within Secure Delegated Quantum Computation (SDQC). Existing SDQC protocols often require servers to perform complex operations like isolating single photons and performing polarisation-preserving photon-number quantum non-demolition measurements. This new approach bypasses those hurdles by relying on interacting quantum emitters capable of generating spin-photon entanglement. The protocol allows a client to manipulate only an attenuated laser pulse while maintaining information-theoretic composable security, hinting at readiness for experimental implementation given recent demonstrations of large entangled photonic states. This represents a significant reduction in the quantum technological capabilities traditionally required of the client in Secure Delegated Quantum Computation (SDQC) schemes, which often demand single-qubit sources or measurements. Existing SDQC protocols aim to enable users to use remote quantum servers without compromising data security or algorithm integrity, but frequently impose substantial hardware demands on the user. The Quandela protocol instead relies on the server handling interacting quantum emitters structured to generate spin-photon entanglement, a potentially more feasible configuration for current and near-future quantum hardware. Page 2 of “Towards practical secure delegated quantum computing with semi-classical light” — Source: arxiv.org…