יום רביעי, 11.1.2012, 12:30
I will present a new approach for creating chosen ciphertext secure encryption.
The focal point of our work is a new abstraction that we call Detectable Chosen
Ciphertext Security (DCCA). Intuitively, this notion is meant to capture systems
that are not necessarily chosen ciphertext attack (CCA) secure, but where we can detect
whether a certain query CT can be useful for decrypting (or distinguishing) a challenge
We show how to build chosen ciphertext secure systems from DCCA security. We motivate
our techniques by describing multiple examples of DCCA systems including creating them
from 1-bit CCA secure encryption - capturing the recent Myers-shelat result (FOCS 2009).
Our work identifies DCCA as a new target for building CCA secure systems.
(This is joint work with Susan Hohenberger and Allison Lewko.)