In this work, we show how to use techniques from threshold ECDSA: (1) to protect keys such that domains do not reveal their signing keys to a DNS operator, and (2) to protect the operational integrity of DNS operator. As a result of being highly specialized, prior work on threshold ECDSA has focused on a limited set of threat models, and none have so far considered techniques to amortize signature generation.creation. Our work takes a different approach and presents a generic technique for obtaining a threshold ECDSA protocol from any secure multiparty computation protocol that works over an appropriate finite field. We show how this technique lends itself to very efficient threshold signing protocols by comparing it against state-of-the-art protocols from both academia and industry. For similar threat models, our protocols are as fast as the previous best protocol in terms of signing, and up to an order of magnitude faster for key generation on a fast network. Finally, we show how to integrate our application into a widely used DNS management software and demonstrate through experiments the overhead compared to traditional DNSSECs.
Category / Keywords: cryptographic protocols / Multiparty computation, Threshold ECDSA, Honest majority, Dishonest majority, DNSSEC Original Publication (with minor differences): ESORICS 2020