Chosen-Ciphertext Security from Identity-Based Encryption

Abstract. We propose a simple and efficient construction of a CCAsecure 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 hierarchica...

• Type: Conference
• Year: 2004
• Where: EUROCRYPT
• Authors: Ran Canetti, Shai Halevi, Jonathan Katz
• Keywords: Cryptography, Encryption Schemes, EUROCRYPT 2004, IBE Schemes, Public-key Encryption Scheme