文摘
We propose an efficient public key encryption scheme which is key-dependent message secure against chosen ciphertext attacks (KDM-CCA) with respect to affine functions based on the decisional composite residuosity assumption. Technically, we achieve KDM-CCA security by enhancing a chosen ciphertext secure scheme based on the high entropy hash proof system with three tools: a key-dependent message encoding, an entropy filter and an authenticated encryption secure against related-key attacks.