Secure Two-Party Matrix Multiplication from Lattices and Its Application to Encrypted Control
This enables privacy-preserving control systems for applications like cloud-based industrial automation, though it's an incremental improvement combining existing cryptographic and control techniques.
The authors developed a secure two-party computation protocol for approximate matrix multiplication using lattice-based cryptography, achieving provable security with single-round communication. Their application to encrypted linear control showed reduced client computational complexity while maintaining sufficient precision despite approximation errors.
In this study, we propose a two-party computation protocol for approximate matrix multiplication of fixed-point numbers. The proposed protocol is provably secure under standard lattice-based cryptographic assumptions and enables matrix multiplication at a desired approximation level within a single round of communication. We demonstrate the feasibility of the protocol by applying it to the secure implementation of a linear control law. Our evaluation reveals that the client achieves lower online computational complexity compared to the original controller computation, while ensuring the privacy of controller inputs, outputs, and parameters. Furthermore, a numerical example confirms that the proposed method maintains sufficient precision of control inputs even in the presence of approximation and quantization errors.