Efficient Function-Hiding Functional Encryption: From Inner-Products to Orthogonality
- 554 Downloads
Abstract
We construct functional encryption (FE) schemes for the orthogonality (OFE) relation where each ciphertext encrypts some vector \(\varvec{\mathsf {x}}\) and each decryption key, associated to some vector \(\varvec{\mathsf {y}}\), allows to determine if \(\varvec{\mathsf {x}}\) is orthogonal to \(\varvec{\mathsf {y}}\) or not. Motivated by compelling applications, we aim at schemes which are function hidding, i.e. \(\varvec{\mathsf {y}}\) is not leaked.
Our main contribution are two such schemes, both rooted in existing constructions of FE for inner products (IPFE), i.e., where decryption keys reveal the inner product of \(\varvec{\mathsf {x}}\) and \(\varvec{\mathsf {y}}\). The first construction builds upon the very efficient IPFE by Kim et al. (SCN 2018) but just like the original scheme its security holds in the generic group model (GGM). The second scheme builds on recent developments in the construction of efficient IPFE schemes in the standard model and extends the work of Wee (TCC 2017) in leveraging these results for the construction of FE for Boolean functions. Conceptually, both our constructions can be seen as further evidence that shutting down leakage from inner product values to only a single bit for the orthogonality relation can be done with little overhead, not only in the GGM, but also in the standard model.
We discuss potential applications of our constructions to secure databases and provide efficiency benchmarks. Our implementation shows that the first scheme is extremely fast and ready to be deployed in practical applications.
Notes
Acknowledgements
This work was supported in part by Royal Society grant for international collaboration and by the European Union Horizon 2020 Research and Innovation Programme under grant agreement 780108 (FENTEC). The first author is financed by Project NanoSTIMA (NORTE-01-0145-FEDER-000016) through the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement and the ERDF.
References
- 1.Abdalla, M., Bourse, F., De Caro, A., Pointcheval, D.: Simple functional encryption schemes for inner products. In: Katz, J. (ed.) PKC 2015. LNCS, vol. 9020, pp. 733–751. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-662-46447-2_33CrossRefGoogle Scholar
- 2.Abdalla, M., Bourse, F., Caro, A.D., Pointcheval, D.: Better security for functional encryption for inner product evaluations. IACR Cryptology ePrint Archive 2016, 11 (2016)Google Scholar
- 3.Abdalla, M., Catalano, D., Fiore, D., Gay, R., Ursu, B.: Multi-input functional encryption for inner products: function-hiding realizations and constructions without pairings. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018. LNCS, vol. 10991, pp. 597–627. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96884-1_20CrossRefGoogle Scholar
- 4.Abdalla, M., Gay, R., Raykova, M., Wee, H.: Multi-input inner-product functional encryption from pairings. In: Coron, J.-S., Nielsen, J.B. (eds.) EUROCRYPT 2017. LNCS, vol. 10210, pp. 601–626. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-56620-7_21CrossRefGoogle Scholar
- 5.Agrawal, S., Gorbunov, S., Vaikuntanathan, V., Wee, H.: Functional encryption: new perspectives and lower bounds. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013. LNCS, vol. 8043, pp. 500–518. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40084-1_28CrossRefGoogle Scholar
- 6.Agrawal, S., Libert, B., Stehlé, D.: Fully secure functional encryption for inner products, from standard assumptions. In: Robshaw, M., Katz, J. (eds.) CRYPTO 2016. LNCS, vol. 9816, pp. 333–362. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53015-3_12CrossRefGoogle Scholar
- 7.Boneh, D., Lewi, K., Raykova, M., Sahai, A., Zhandry, M., Zimmerman, J.: Semantically secure order-revealing encryption: multi-input functional encryption without obfuscation. In: Oswald, E., Fischlin, M. (eds.) EUROCRYPT 2015. LNCS, vol. 9057, pp. 563–594. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-662-46803-6_19CrossRefGoogle Scholar
- 8.Boneh, D., Raghunathan, A., Segev, G.: Function-private subspace-membership encryption and its applications. In: Sako, K., Sarkar, P. (eds.) ASIACRYPT 2013. LNCS, vol. 8269, pp. 255–275. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-42033-7_14CrossRefGoogle Scholar
- 9.Boneh, D., Sahai, A., Waters, B.: Functional encryption: definitions and challenges. In: Ishai, Y. (ed.) TCC 2011. LNCS, vol. 6597, pp. 253–273. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-19571-6_16CrossRefGoogle Scholar
- 10.Boneh, D., Waters, B.: Conjunctive, subset, and range queries on encrypted data. In: Vadhan, S.P. (ed.) TCC 2007. LNCS, vol. 4392, pp. 535–554. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-70936-7_29CrossRefGoogle Scholar
- 11.Escala, A., Herold, G., Kiltz, E., Ràfols, C., Villar, J.L.: An algebraic framework for diffie-hellman assumptions. J. Cryptol. 30(1), 242–288 (2017)MathSciNetCrossRefGoogle Scholar
- 12.Katz, J., Sahai, A., Waters, B.: Predicate encryption supporting disjunctions, polynomial equations, and inner products. J. Cryptol. 26(2), 191–224 (2013)MathSciNetCrossRefGoogle Scholar
- 13.Kawai, Y., Takashima, K.: Predicate- and attribute-hiding inner product encryption in a public key setting. In: Cao, Z., Zhang, F. (eds.) Pairing 2013. LNCS, vol. 8365, pp. 113–130. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-04873-4_7CrossRefGoogle Scholar
- 14.Kim, S., Lewi, K., Mandal, A., Montgomery, H.W., Roy, A., Wu, D.J.: Function-hiding inner product encryption is practical. IACR Cryptology ePrint Archive 2016, 440 (2016)Google Scholar
- 15.Lin, H.: Indistinguishability obfuscation from SXDH on 5-linear maps and locality-5 PRGs. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017. LNCS, vol. 10401, pp. 599–629. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63688-7_20CrossRefGoogle Scholar
- 16.Lin, H., Vaikuntanathan, V.: Indistinguishability obfuscation from DDH-like assumptions on constant-degree graded encodings. In: Proceedings of IEEE 57th Annual Symposium on Foundations of Computer Science, FOCS 2016, pp. 11–20 (2016)Google Scholar
- 17.Okamoto, T., Takashima, K.: Adaptively attribute-hiding (hierarchical) inner product encryption. In: Pointcheval, D., Johansson, T. (eds.) EUROCRYPT 2012. LNCS, vol. 7237, pp. 591–608. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-29011-4_35CrossRefGoogle Scholar
- 18.Okamoto, T., Takashima, K.: Efficient (hierarchical) inner-product encryption tightly reduced from the decisional linear assumption. IEICE Trans. 96–A(1), 42–52 (2013)CrossRefGoogle Scholar
- 19.O’Neill, A.: Definitional issues in functional encryption. IACR Cryptology ePrint Archive 2010, 556 (2010)Google Scholar
- 20.Shen, E., Shi, E., Waters, B.: Predicate privacy in encryption systems. In: Reingold, O. (ed.) TCC 2009. LNCS, vol. 5444, pp. 457–473. Springer, Heidelberg (2009). https://doi.org/10.1007/978-3-642-00457-5_27CrossRefGoogle Scholar
- 21.Shi, E., Bethencourt, J., Chan, T.H.H., Song, D., Perrig, A.: Multi-dimensional range query over encrypted data. In: Proceedings of the 2007 IEEE Symposium on Security and Privacy, SP 2007, pp. 350–364. IEEE Computer Society, Washington, DC, USA (2007). https://doi.org/10.1109/SP.2007.29
- 22.Wee, H.: Attribute-hiding predicate encryption in bilinear groups, revisited. In: Kalai, Y., Reyzin, L. (eds.) TCC 2017. LNCS, vol. 10677, pp. 206–233. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-70500-2_8CrossRefGoogle Scholar