Towards Practical Post-quantum Signatures for Resource-Limited Internet of Things

A digital signature is an essential cryptographic tool to offer authentication with public verifiability, non-repudiation, and scalability. However, digital signatures often rely on expensive operations that can be highly costly for low-end devices, typically seen in the Internet of Things and Systems (IoTs). These efficiency concerns especially deepen when post-quantum secure digital signatures are considered. Hence, it is of vital importance to devise post-quantum secure digital signatures that are designed with the needs of such constraint IoT systems in mind. In this work, we propose a novel lightweight post-quantum digital signature that respects the processing, memory, and bandwidth limitations of resource-limited IoTs. Our new scheme, called ANT, efficiently transforms a one-time signature to a (polynomially-bounded) many-time signature via a distributed public key computation method. This new approach enables a resource-limited signer to compute signatures without any costly lattice operations (e.g., rejection samplings, matrix multiplications, etc.), and only with a low-memory footprint and compact signature sizes. We also developed a variant for ANT with forward-security, which is an extremely costly property to attain via the state-of-the-art post-quantum signatures.