Abstract
In this work, we take a closer look at anonymity and robustness in encryption schemes. Roughly speaking, an anonymous encryption scheme hides the identity of the secret-key holder, while a robust encryption scheme guarantees that every ciphertext can only be decrypted to a valid plaintext under the intended recipient’s secret key.
In case of anonymous encryption, we show that if an anonymous PKE or IBE scheme (in presence of CCA attacks) is used in a hybrid encryption, all bets regarding the anonymity of the resulting encryption are off. We show that this is the case even if the symmetric-key component is anonymous. On the positive side, however, we prove that if the key-encapsulation method is, additionally weakly robust the resulting hybrid encryption remains anonymous. Some of the existing anonymous encryption schemes are known to be weakly robust which makes them more desirable in practice.
In case of robust encryption, we design several efficient constructions for transforming any PKE/IBE scheme into weakly and strongly robust ones. Our constructions only add a minor computational overhead to the original schemes, while achieving better ciphertext sizes compared to the previous constructions. An important property of our transformations is that they are non-keyed and do not require any modifications to the public parameters of the original schemes.
We also introduce a relaxation of the notion of robustness we call collision-freeness. We primarily use collision-freeness as an intermediate notion by showing a more efficient construction for transforming any collision-free encryption scheme into a strongly robust one. We believe that this simple notion can be a plausible replacement for robustness in some scenarios in practice. The advantage is that most existing schemes seem to satisfy collision-freeness without any modifications.
Chapter PDF
Similar content being viewed by others
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
References
Abadi, M., Rogaway, P.: Reconciling two views of cryptography (the computational soundness of formal encryption) 20(3) 395 (2007)
Abdalla, M., Bellare, M., Catalano, D., Kiltz, E., Kohno, T., Lange, T., Malone-Lee, J., Neven, G., Paillier, P., Shi, H.: Searchable encryption revisited: Consistency properties, relation to anonymous IBE, and extensions, vol. 21(3), pp. 350–391 (2008)
Abdalla, M., Bellare, M., Neven, G.: Robust encryption. In: Micciancio, D. (ed.) Theory of Cryptography. LNCS, vol. 5978, pp. 480–497. Springer, Heidelberg (2010)
Abdalla, M., Bellare, M., Rogaway, P.: The oracle Diffie-Hellman assumptions and an analysis of DHIES, pp. 143–158 (2001)
Bellare, M., Boldyreva, A., Desai, A., Pointcheval, D.: Key-privacy in public-key encryption, pp. 566–582 (2001)
Bellare, M., Rogaway, P.: Random oracles are practical: A paradigm for designing efficient protocols, pp. 62–73 (1993)
Bellare, M., Rogaway, P.: Optimal asymmetric encryption, pp. 92–111 (1994)
Boneh, D., Franklin, M.K.: Identity-based encryption from the Weil pairing, pp. 213–229 (2001)
Boyen, X., Waters, B.: Anonymous hierarchical identity-based encryption (without random oracles), pp. 290–307 (2006)
Cramer, R., Shoup, V.: Design and analysis of practical public-key encryption schemes secure against adaptive chosen ciphertext attack, vol. 33(1), pp. 167–226 (2003)
Desai, A.: The security of all-or-nothing encryption: Protecting against exhaustive key search, pp. 359–375 (2000)
Dolev, D., Dwork, C., Naor, M.: Non-malleable cryptography (1998) (manuscript)
El Gamal, T.: A public key cryptosystem and a signature scheme based on discrete logarithms, vol. 31, pp. 469–472 (1985)
Fischlin, M.: Pseudorandom function tribe ensembles based on one-way permutations: Improvements and applications, pp. 432–445 (1999)
Goldwasser, S., Micali, S.: Probabilistic encryption. Journal of Computer and System Sciences 28(2), 270–299 (1984)
Håstad, J., Impagliazzo, R., Levin, L.A., Luby, M.: A pseudorandom generator from any one-way function, vol. 28(4), pp. 1364–1396 (1999)
Hofheinz, D., Weinreb, E.: Searchable encryption with decryption in the standard model. Cryptology ePrint Archive, Report 2008/423 (2008), http://eprint.iacr.org/
Katz, J., Sahai, A., Waters, B.: Predicate encryption supporting disjunctions, polynomial equations, and inner products, pp. 146–162 (2008)
Rackoff, C., Simon, D.R.: Non-interactive zero-knowledge proof of knowledge and chosen ciphertext attack, pp. 433–444 (1992)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 International Association for Cryptologic Research
About this paper
Cite this paper
Mohassel, P. (2010). A Closer Look at Anonymity and Robustness in Encryption Schemes. In: Abe, M. (eds) Advances in Cryptology - ASIACRYPT 2010. ASIACRYPT 2010. Lecture Notes in Computer Science, vol 6477. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-17373-8_29
Download citation
DOI: https://doi.org/10.1007/978-3-642-17373-8_29
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-17372-1
Online ISBN: 978-3-642-17373-8
eBook Packages: Computer ScienceComputer Science (R0)