We propose a new variant of the Cramer-Shoup KEM (key encapsulation mechanism). The proposed variant is more efficient than the original Cramer-Shoup KEM scheme in terms of public key size and encapsulation cost, but is proven to be (still) secure against chosen ciphertext attack in the standard model, relative to the Decisional Diffie-Hellman problem.
Joonsang Baek, Willy Susilo, Joseph K. Liu, Jianyi