Refining Mosca’s Theorem: Risk Management Model for the Quantum Threat Applied to IoT Protocol Security

Abstract

Large-scale quantum computation (QC) presents a serious threat to many modern cryptographic primitives. This has profound implications to the critical information infrastructure (CII) as well. The main mitigation techniques involve migrating to cryptographic schemes that are postulated to be “quantum resilient”, i.e. there are no known quantum algorithms for them. The solution requires that all the known instances of the vulnerable cryptographic schemes are replaced with quantum resistant schemes. In a lecture at the NIST premises in 2015, Dr. Mosca gave his famous theorem of when different stakeholders should start upgrading their systems. This theorem is, however, very general and assumes the worst possible scenario. Does it apply equally well for all or even the majority of use cases of cryptography? Is the answer same across all domains of CII or all types of networks? Currently the most challenging environments are those with very little computational and networking capabilities, i.e. Internet-of-Things (IoT). IoT is today used in many CI subcategories, such as power grid (including SCADA), water supply, logistics, agriculture and dangerous goods handling. In this text, we develop a more detailed risk management model to prepare for QC and apply this model to survey the status of Internet-of-Things (IoT) protocols. We cover in total 17 different IoT protocols or protocol families.