Public-Key Encryption Indistinguishable Under Plaintext-Checkable Attacks
Indistinguishability under adaptive chosen-ciphertext attack (IND-CCA) is now considered the de facto security notion for public-key encryption. However, the security guarantee that it offers is sometimes stronger than what is needed by certain applications. In this paper, we consider a weaker notion of security for public-key encryption, termed indistinguishability under plaintext-checking attacks (IND-PCA), in which the adversary is only given access to an oracle which says whether or not a given ciphertext encrypts a given message. After formalizing the IND-PCA notion, we then design a new public-key encryption scheme satisfying it. The new scheme is a more efficient variant of the Cramer-Shoup encryption scheme with shorter ciphertexts and its security is also based on the plain Decisional Diffie-Hellman (DDH) assumption. Additionally, the algebraic properties of the new scheme also allow for proving plaintext knowledge using Groth-Sahai non-interactive zero-knowledge proofs or smooth projective hash functions. Finally, in order to illustrate the usefulness of the new scheme, we further show that, for many password-based authenticated key exchange (PAKE) schemes in the Bellare-Pointcheval-Rogaway security model, one can safely replace the underlying IND-CCA encryption schemes with our new IND-PCA one. By doing so, we were able to reduce the overall communication complexity of these protocols and obtain the most efficient PAKE schemes to date based on the plain DDH assumption.
KeywordsEntropy Assure Extractor Tame Tocol
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- 1.Abdalla, M., Benhamouda, F., Pointcheval, D.: Public-key encryption scheme indistinguishable under plaintext-checkable attacks. Cryptology ePrint Archive, Report 2014/609 (2014). http://eprint.iacr.org/2014/609
- 7.Bellare, M., Rogaway, P.: Code-based game-playing proofs and the security of triple encryption. Cryptology ePrint Archive, Report 2004/331 (2004). http://eprint.iacr.org/2004/331
- 13.Dolev, D., Dwork, C., Naor, M.: Non-malleable cryptography (extended abstract). In: 23rd ACM STOC, pp. 542–552. ACM Press, May 1991Google Scholar
- 15.El Gamal, T.: A public key cryptosystem and a signature scheme based on discrete logarithms. In: Blakely, G.R., Chaum, D. (eds.) CRYPTO 1984. LNCS, vol. 196, pp. 10–18. Springer, Heidelberg (1985) Google Scholar
- 19.Groce, A., Katz, J.: A new framework for efficient password-based authenticated key exchange. In: Al-Shaer, E., Keromytis, A.D., Shmatikov, V. (eds.) ACM CCS 2010, pp. 516–525. ACM Press, October 2010Google Scholar
- 27.Naor, M., Reingold, O.: Number-theoretic constructions of efficient pseudo-random functions. In: 38th FOCS, pp. 458–467. IEEE Computer Society Press, October 1997Google Scholar
- 28.Naor, M., Yung, M.: Public-key cryptosystems provably secure against chosen ciphertext attacks. In: 22nd ACM STOC, pp. 427–437. ACM Press, May 1990Google Scholar
- 30.Rackoff, C., Simon, D.R.: Non-interactive zero-knowledge proof of knowledge and chosen ciphertext attack. In: Feigenbaum, J. (ed.) CRYPTO 1991. LNCS, vol. 576, pp. 433–444. Springer, Heidelberg (1992) Google Scholar
- 31.Shoup, V.: Sequences of games: a tool for taming complexity in security proofs. Cryptology ePrint Archive, Report 2004/332 (2004). http://eprint.iacr.org/2004/332