Dr. Kemal Akkaya
Funding: DOE

Secure smart meter communications rely on keys for encryption, decryption, authentication and so forth, but the management of keys is a challenge. This project addresses public key distribution in smart meter networks, and in particular, how to revoke breached and expired public keys. It aims to develop customized solutions for certificate revocation lists (CRLs) management that will secure the communications in Advanced Metering Infrastructure (AMI) with high efficiency. So far, we investigated bloom filters and distributed hash tables to replace the CRL with a more efficient approach. In this project, we propose a novel idea to further reduce the size of CRLs by exploiting cryptographic accumulators inspired byblockchain. The concept provides an efficient mechanism to check whether an element is a member of a specific set. Although cryptographic accumulators provide a very efficient membership test (i.e., whitelist), we need a scheme that provides a non-membership test (i.e., blacklist) to allow working with conventional CRLs where a certificate is deemed valid if it is not in the CRL. To enable an accumulator with non-membership proof capability, we construct an accumulator scheme that provides a non-membership witness for each value not on the list. In a nutshell, we propose condensing the entire CRL into a single accumulator value to avoid unmanageable CRL size for the smart meters.