Abstract

Lossy trapdoor functions enable black-box construction of public key encryption (PKE) schemessecure against chosen-ciphertext attack [18]. Recently, a more efficient black-box construction ofpublic key encryption was given in [13] with the help of chameleon all-but-one trapdoor functions(ABO-TDFs). In this paper, we propose a black-box construction for transforming any ABO-TDFsinto chameleon ABO-TDFs with the help of chameleon hash functions. Instantiating the proposedgeneral black-box construction of chameleon ABO-TDFs, we obtain the first chameleon ABO-TDFsbased on the Decisional Diffie-Hellman (DDH) assumption.