A Key-Switching Protocol for the Homomorphic Encryption of IoT Data

https://doi.org/10.65161/rechCrkKXDTGPLXBH

The Internet of Things (IoT) is a growing field, and, as such, we must prioritise the security of data held within these devices due to their vulnerability, as they are commonly low-powered or unprotected. There exist homomorphic encryption schemes that allow secure computations on data from IoT devices. Still, they come at the cost of latency, and those with low latency come at the cost of security. The protocol presented in this paper suggests a way to reduce overhead latency timings whilst maintaining security during data transmission. This is done through key-switching, allowing the data owner to choose parties who are allowed to act on the plaintext rather than the ciphertext.

Additionally, if a party is not trusted, the client and server can continue computing on homomorphically encrypted data, allowing for an uninterrupted workflow. The outlined protocol is created using the OpenFHE Library in C++ and tested on Google Cloud against the protocol in [1]. The protocol improves system performance, with an average 53.86% reduction in average latency and an average 5.98 percentage point reduction in average CPU utilisation.