Adaptive Trapdoor Functions and Chosen-Ciphertext Security

We introduce the notion of adaptive trapdoor functions (ATDFs); roughly, ATDFs remain one-way even when the adversary is given access to an inversion oracle. Our main application is the black-box construction of chosenciphertext secure public-key encryption (CCA-secure PKE). Namely, we give a black-box construction of CCA-Secure PKE from ATDFs, as well as a construction of ATDFs from correlation-secure TDFs introduced by Rosen and Segev (TCC ’09). Moreover, by an extension of a recent result of Vahlis (TCC ’10), we show that ATDFs are strictly weaker than the latter (in a black-box sense). Thus, adaptivity appears to be the weakest condition on a TDF currently known to yield the first implication. We also give a black-box construction of CCA-secure PKE from a natural generalization of ATDFs we call tag-based ATDFs that, when applied to our constructions of the latter from either correlation-secure TDFs, or lossy TDFs introduced by Peikert and Waters (STOC ’08), yield precisely ...

• Type: Conference
• Year: 2010
• Where: EUROCRYPT
• Authors: Eike Kiltz, Payman Mohassel, Adam O'Neill
• Keywords: Black-box Construction, Cca-secure Pke, Correlation-secure Tdfs, Cryptology, EUROCRYPT 2010