Ouroboros Crypsinous: Privacy-Preserving Proof-of-Stake presented at IEEESymposium 2019

by Markulf Kohlweiss, Aggelos Kiayias, Vassilis Zikas, Thomas Kerber,

URL : https://youtu.be/hJaPu3T8Uuo

Summary : We present Ouroboros Crypsinous, the first formally analyzed privacy-preserving proof-of-stake blockchain protocol. To model its security we give a thorough treatment of private ledgers in the (G)UC setting that might be of independent interest.To prove our protocol secure against adaptive attacks, we introduce a new coin evolution technique relying on SNARKs and key-private forward secure encryption. The latter primitive—and the associated construction—can be of independent interest. We stress that existing approaches to private blockchain, such as the proof-of-work-based Zerocash are analyzed only against static corruptions.