Multi-Recipient Encryption Schemes: Security Notions and Randomness Re-Use
Mihir Bellare, Alexandra Boldyreva, Jessica Staddon · 2003
This paper begins by rening Kurosawa’s [Ku] denitions of security for multi-recipient encryption schemes (MRESs). It then considers a subclass of MRESs, that are formed by transforming standard encryption schemes via a natural technique called randomness re-use, and that oer important performance benets. The main result is a way to avoid ad-hoc analyses of such schemes: we provide a general test that can be applied to a standard encryption scheme to determine whether the associated randomness re-using MRES is secure. This is applied to identify numerous specic secure and ecient randomness re-using MRESs. The results and applications cover both asymmetric and symmetric encryption.