International Association
for Cryptologic Research

This paper defines adaptive soundness (AS) security for witness encryption and applies it to provide the first non-invasive schemes for asymmetric password-based encryption (A-PBE). A-PBE offers significant gains over classical, symmetric password-based encryption (S-PBE) in the face of attacks that compromise servers to recover hashed passwords. We also show by counter-example that the original soundness security (SS) requirement of GGSW does not suffice for the security of their own applications, and show that AS fills the gap.