Lightweight Digital Signatures for Internet of Things: Current and Post-Quantum Trends and Visions

The Internet of Things (IoT) harbors a large number of resource-limited devices (e.g., sensors) that continuously generate and off load sensitive information (e.g., financial, health, personal). It is imperative the ensure the trustworthiness of this data with efficient cryptographic mechanisms. Digital signatures can offer scalable authentication with public verifiability and non-repudiation. However, the state-of-the-art digital signatures do not offer the desired efficiency and are not scalable for the connected resource-limited IoT devices. This is without considering long-term security features such as post-quantum security and forward security. In this paper, we summarize the main challenges to an energy-aware and efficient signature scheme. Then, we propose new scheme design improvements that uniquely embed different emerging technologies such as Mutli-Party Computation (MPC) and secure enclaves (e.g., Intel SGX) in order to secret-share confidential keys of low-end IoT devices across multiple cloud servers. We also envision building signature schemes with Fully Homomorphic Encryption (FHE) to enable verifiers to compute expensive commitments under encryption. We provide evaluation metrics that showcase the feasibility and efficiency of our designs for potential deployment on embedded devices in IoT.