A Light-Weight White-Box Encryption Scheme for Securing Distributed Embedded Devices

摘要

Distributed embedded devices are widely used in sensor networks and the Internet of Things for gathering and sending data. Many of them are deployed in an unattended manner (e.g., sensor nodes and tag readers), while others may be easily lost (e.g., smart wristbands and watches). These distributed embedded devices could be potentially captured and accessed in an unauthorized manner due to their physical natures. From a security perspective, they are typically working in the white-box attack context, where adversaries have total visibility on the implementations of built-in cryptosystems and full control over their execution processes. It is undoubtedly a significant challenge to deal with white-box attacks on these devices. Existing encryption algorithms for white-box attack contexts require large memory footprint and thus are not suitable for resource-constrained embedded devices. To address this challenge, we propose a novel light-weight encryption scheme for protecting data confidentiality. The encryption is conducted with specialized secret components, and the encryption algorithm requires a small volume of static data for storing critical information. In addition, this scheme uniquely supports efficient key-updating at very small cost. The security and the cost of the proposed scheme have been theoretically analyzed with positive results, and the extensive experimental evaluations indicate that the new scheme satisfies the requirements of distributed embedded devices in terms of limited memory usage and low computational cost.