%0 Journal Article %J Advances in Cryptology-Eurocrypt 2004 %D 2004 %T Chosen-ciphertext security from identity-based encryption %A Canetti,R. %A Halevi,S. %A Katz, Jonathan %X We propose a simple and efficient construction of a CCA-secure public-key encryption scheme from any CPA-secure identity-based encryption (IBE) scheme. Our construction requires the underlying IBE scheme to satisfy only a relatively “weak” notion of security which is known to be achievable without random oracles; thus, our results provide a new approach for constructing CCA-secure encryption schemes in the standard model. Our approach is quite different from existing ones; in particular, it avoids non-interactive proofs of “well-formedness” which were shown to underlie most previous constructions. Furthermore, applying our conversion to some recently-proposed IBE schemes results in CCA-secure schemes whose efficiency makes them quite practical.Our technique extends to give a simple and reasonably efficient method for securing any binary tree encryption (BTE) scheme against adaptive chosen-ciphertext attacks. This, in turn, yields more efficient CCA-secure hierarchical identity-based and forward-secure encryption schemes in the standard model. %B Advances in Cryptology-Eurocrypt 2004 %P 207 - 222 %8 2004/// %G eng %R 10.1007/978-3-540-24676-3_13