Abstract
Multi-Client Functional Encryption (\(\textsf {MCFE}\)) and Multi-Input Functional Encryption (\(\textsf {MIFE}\)) are very interesting extensions of Functional Encryption for practical purpose. They allow to compute joint function over data from multiple parties. Both primitives are aimed at applications in multi-user settings where decryption can be correctly output for users with appropriate functional decryption keys only. While the definitions for a single user or multiple users were quite general and can be realized for general classes of functions as expressive as Turing machines or all circuits, efficient schemes have been proposed so far for concrete classes of functions: either only for access control, i.e. the identity function under some conditions, or linear/quadratic functions under no condition.
In this paper, we target classes of functions that explicitly combine some evaluation functions independent of the decrypting user under the condition of some access control. More precisely, we introduce a framework for \(\textsf {MCFE}\) with fine-grained access control and propose constructions for both single-client and multi-client settings, for inner-product evaluation and access control via Linear Secret Sharing Schemes (LSSS), with selective and adaptive security. The only known work that combines functional encryption in multi-user setting with access control was proposed by Abdalla et al. (Asiacrypt ’20), which relies on a generic transformation from the single-client schemes to obtain \(\textsf {MIFE} \) schemes that suffer a quadratic factor of n (where n denotes the number of clients) in the ciphertext size. We follow a different path, via \(\textsf {MCFE} \): we present a duplicate-and-compress technique to transform the single-client scheme and obtain a \(\textsf {MCFE}\) with fine-grained access control scheme with only a linear factor of n in the ciphertext size. Our final scheme thus outperforms the Abdalla et al.’s scheme by a factor n, as one can obtain \(\textsf {MIFE}\) from \(\textsf {MCFE}\) by making all the labels in \(\textsf {MCFE}\) a fixed public constant. The concrete constructions are secure under the \(\textsf{SXDH}\) assumption, in the random oracle model for the \(\textsf {MCFE}\) scheme, but in the standard model for the \(\textsf {MIFE}\) improvement.
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Notes
- 1.
See [1, 12] for discussions about this relaxation. The general reason is that some functionality might contain \(\bot \) in its range and if \(F_\lambda (x) = \bot \) we do not impose \(\textsf{Dec}(\textsf{sk}_{F_\lambda ,\mathsf {ac{-}k}},\textsf{Enc}(\textsf{pk}, x, \mathsf {ac{-}ct})) = F_\lambda (x)\), neither do we disallow it..
- 2.
If all clients must use the same set of attributes , we can treat as a virtual attribute in \(\textsf{S}\), while enforcing the same for all i. This implies that all must be the same. However, this approach requires a consensus among all n clients on \(\textsf{S}\), which general might be more complicated than agreeing on \(\textsf{tag}\).
- 3.
Since our single-client scheme is public-key, we can obtain multi-challenge security using a standard hybrid argument.
- 4.
For instance, the adversary might corrupt \(i^*\), query a left-or-right challenge \((\textbf{x}_0,\textbf{x}_1)\) where \(\varDelta \textbf{x}[i^*] {:}{=}\textbf{x}_0[i^*] - \textbf{x}_1[i^*]\ne 0\) and \(\varDelta \textbf{x}[i] = 0\) for \(i\ne i^*\), then decrypt the challenge ciphertext with a satisfied key for \(\textbf{y}^{\scriptscriptstyle (\ell )}\) whose \(i^*\)-th entry is non-zero.
References
Abdalla, M., Bellare, M., Neven, G.: Robust encryption. In: Micciancio, D. (ed.) TCC 2010. LNCS, vol. 5978, pp. 480–497. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-11799-2_28
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_33
Abdalla, M., Bourse, F., De Caro, A., Pointcheval, D.: Better security for functional encryption for inner product evaluations. Cryptology ePrint Archive, Report 2016/011 (2016). https://eprint.iacr.org/2016/011
Abdalla, M., Catalano, D., Gay, R., Ursu, B.: Inner-product functional encryption with fine-grained access control. In: Moriai, S., Wang, H. (eds.) ASIACRYPT 2020, Part III. LNCS, vol. 12493, pp. 467–497. Springer, Heidelberg (2020). https://doi.org/10.1007/978-3-030-64840-4_16
Agrawal, S., Kitagawa, F., Modi, A., Nishimaki, R., Yamada, S., Yamakawa, T.: Bounded functional encryption for turing machines: Adaptive security from general assumptions. Cryptology ePrint Archive, Report 2022/316 (2022). https://ia.cr/2022/316
Agrawal, S., Libert, B., Stehlé, D.: Fully secure functional encryption for inner products, from standard assumptions. In: Robshaw, M., Katz, J. (eds.) CRYPTO 2016, Part III. LNCS, vol. 9816, pp. 333–362. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53015-3_12
Agrawal, S., Maitra, M., Vempati, N.S., Yamada, S.: Functional encryption for turing machines with dynamic bounded collusion from LWE. In: Malkin, T., Peikert, C. (eds.) CRYPTO 2021, Part IV. LNCS, vol. 12828, pp. 239–269. Springer, Heidelberg, Virtual Event (2021). https://doi.org/10.1007/978-3-030-84259-8_9
Ananth, P., Sahai, A.: Projective arithmetic functional encryption and indistinguishability obfuscation from degree-5 multilinear maps. In: Coron, J.S., Nielsen, J.B. (eds.) EUROCRYPT 2017, Part I. LNCS, vol. 10210, pp. 152–181. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-319-56620-7_6
Attrapadung, N., Libert, B., de Panafieu, E.: Expressive key-policy attribute-based encryption with constant-size ciphertexts. In: Catalano, D., Fazio, N., Gennaro, R., Nicolosi, A. (eds.) PKC 2011. LNCS, vol. 6571, pp. 90–108. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-19379-8_6
Baltico, C.E.Z., Catalano, D., Fiore, D., Gay, R.: Practical functional encryption for quadratic functions with applications to predicate encryption. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017, Part I. LNCS, vol. 10401, pp. 67–98. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-319-63688-7_3
Beimel, A.: Secure Schemes for Secret Sharing and Key Distribution. Ph.D. thesis, Technion - Israel Institute of Technology, Haifa, Israel (June 1996). https://www.cs.bgu.ac.il/~beimel/Papers/thesis.pdf
Bellare, M., O’Neill, A.: Semantically-secure functional encryption: Possibility results, impossibility results and the quest for a general definition. In: Abdalla, M., Nita-Rotaru, C., Dahab, R. (eds.) CANS 13. LNCS, vol. 8257, pp. 218–234. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-319-02937-5_12
Benaloh, J.C., Leichter, J.: Generalized secret sharing and monotone functions. In: Goldwasser, S. (ed.) CRYPTO’88. LNCS, vol. 403, pp. 27–35. Springer, Heidelberg (1990). https://doi.org/10.1007/0-387-34799-2_3
Benhamouda, F., Bourse, F., Lipmaa, H.: CCA-secure inner-product functional encryption from projective hash functions. In: Fehr, S. (ed.) PKC 2017, Part II. LNCS, vol. 10175, pp. 36–66. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-662-54388-7_2
Boneh, D., Franklin, M.K.: Identity-based encryption from the Weil pairing. In: Kilian, J. (ed.) CRYPTO 2001. LNCS, vol. 2139, pp. 213–229. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-44647-8_13
Boneh, D., Gentry, C., Hamburg, M.: Space-efficient identity based encryption without pairings. In: 48th FOCS. pp. 647–657. IEEE Computer Society Press (2007). https://doi.org/10.1109/FOCS.2007.64
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_16
Castagnos, G., Laguillaumie, F., Tucker, I.: Practical fully secure unrestricted inner product functional encryption modulo p. In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018, Part II. LNCS, vol. 11273, pp. 733–764. Springer, Heidelberg (2018). https://doi.org/10.1007/978-3-030-03329-3_25
Chen, J., Lim, H.W., Ling, S., Wang, H., Wee, H.: Shorter IBE and signatures via asymmetric pairings. In: Abdalla, M., Lange, T. (eds.) PAIRING 2012. LNCS, vol. 7708, pp. 122–140. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-36334-4_8
Chotard, J., Dufour Sans, E., Gay, R., Phan, D.H., Pointcheval, D.: Decentralized multi-client functional encryption for inner product. In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018, Part II. LNCS, vol. 11273, pp. 703–732. Springer, Heidelberg (2018). https://doi.org/10.1007/978-3-030-03329-3_24
Chotard, J., Dufour Sans, E., Gay, R., Phan, D.H., Pointcheval, D.: Multi-client functional encryption with repetition for inner product. Cryptology ePrint Archive, Report 2018/1021 (2018). https://eprint.iacr.org/2018/1021
Chotard, J., Dufour-Sans, E., Gay, R., Phan, D.H., Pointcheval, D.: Dynamic decentralized functional encryption. In: Micciancio, D., Ristenpart, T. (eds.) CRYPTO 2020, Part I. LNCS, vol. 12170, pp. 747–775. Springer, Heidelberg (2020). https://doi.org/10.1007/978-3-030-56784-2_25
Cocks, C.: An identity based encryption scheme based on quadratic residues. In: Honary, B. (ed.) Cryptography and Coding 2001. LNCS, vol. 2260, pp. 360–363. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-45325-3_32
Delerablée, C., Gouriou, L., Pointcheval, D.: Key-policy ABE with delegation of rights. Cryptology ePrint Archive, Report 2021/867 (2021). https://ia.cr/2021/867
Escala, A., Herold, G., Kiltz, E., Ràfols, C., Villar, J.: An algebraic framework for Diffie-Hellman assumptions. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013, Part II. LNCS, vol. 8043, pp. 129–147. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40084-1_8
Gay, R.: A new paradigm for public-key functional encryption for degree-2 polynomials. In: Kiayias, A., Kohlweiss, M., Wallden, P., Zikas, V. (eds.) PKC 2020, Part I. LNCS, vol. 12110, pp. 95–120. Springer, Heidelberg (2020). https://doi.org/10.1007/978-3-030-45374-9_4
Goldwasser, S., Gordon, S.D., Goyal, V., Jain, A., Katz, J., Liu, F.H., Sahai, A., Shi, E., Zhou, H.S.: Multi-input functional encryption. In: Nguyen, P.Q., Oswald, E. (eds.) EUROCRYPT 2014. LNCS, vol. 8441, pp. 578–602. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-642-55220-5_32
Gordon, S.D., Katz, J., Liu, F.H., Shi, E., Zhou, H.S.: Multi-input functional encryption. Cryptology ePrint Archive, Report 2013/774 (2013). https://eprint.iacr.org/2013/774
Goyal, V., Pandey, O., Sahai, A., Waters, B.: Attribute-based encryption for fine-grained access control of encrypted data. In: Juels, A., Wright, R.N., De Capitani di Vimercati, S. (eds.) ACM CCS 2006. pp. 89–98. ACM Press (2006). https://doi.org/10.1145/1180405.1180418, available as Cryptology ePrint Archive Report 2006/309
Lai, Q., Liu, F.H., Wang, Z.: New lattice two-stage sampling technique and its applications to functional encryption - stronger security and smaller ciphertexts. In: Canteaut, A., Standaert, F.X. (eds.) EUROCRYPT 2021, Part I. LNCS, vol. 12696, pp. 498–527. Springer, Heidelberg (2021). https://doi.org/10.1007/978-3-030-77870-5_18
Lewko, A.B., Waters, B.: New techniques for dual system encryption and fully secure HIBE with short ciphertexts. In: Micciancio, D. (ed.) TCC 2010. LNCS, vol. 5978, pp. 455–479. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-11799-2_27
Libert, B., Titiu, R.: Multi-client functional encryption for linear functions in the standard model from LWE. In: Galbraith, S.D., Moriai, S. (eds.) ASIACRYPT 2019, Part III. LNCS, vol. 11923, pp. 520–551. Springer, Heidelberg (2019). https://doi.org/10.1007/978-3-030-34618-8_18
Lin, H.: Indistinguishability obfuscation from SXDH on 5-linear maps and locality-5 PRGs. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017, Part I. LNCS, vol. 10401, pp. 599–629. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-319-63688-7_20
Nguyen, K., Phan, D.H., Pointcheval, D.: Multi-client functional encryption with fine-grained access control. Cryptology ePrint Archive, Report 2022/215 (2022). https://eprint.iacr.org/2022/215
Okamoto, T., Takashima, K.: Fully secure functional encryption with general relations from the decisional linear assumption. In: Rabin, T. (ed.) CRYPTO 2010. LNCS, vol. 6223, pp. 191–208. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14623-7_11
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_35
Okamoto, T., Takashima, K.: Fully secure unbounded inner-product and attribute-based encryption. In: Wang, X., Sako, K. (eds.) ASIACRYPT 2012. LNCS, vol. 7658, pp. 349–366. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-34961-4_22
Ostrovsky, R., Sahai, A., Waters, B.: Attribute-based encryption with non-monotonic access structures. In: Ning, P., De Capitani di Vimercati, S., Syverson, P.F. (eds.) ACM CCS 2007. pp. 195–203. ACM Press (2007). https://doi.org/10.1145/1315245.1315270
Pal, T., Dutta, R.: Attribute-based access control for inner product functional encryption from LWE. In: LATIN 2021 (2021)
Sahai, A., Waters, B.R.: Fuzzy identity-based encryption. In: Cramer, R. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 457–473. Springer, Heidelberg (2005). https://doi.org/10.1007/11426639_27
Shamir, A.: How to share a secret. Commun. Assoc. Comput. Mach. 22(11), 612–613 (1979)
Shamir, A.: Identity-based cryptosystems and signature schemes. In: Blakley, G.R., Chaum, D. (eds.) CRYPTO’84. LNCS, vol. 196, pp. 47–53. Springer, Heidelberg (1984)
Waters, B.: Dual system encryption: realizing fully secure IBE and HIBE under simple assumptions. In: Halevi, S. (ed.) CRYPTO 2009. LNCS, vol. 5677, pp. 619–636. Springer, Heidelberg (2009). https://doi.org/10.1007/978-3-642-03356-8_36
Wee, H.: Broadcast encryption with size \({N}^{1/3}\) and more from \(k\)-lin. In: Malkin, T., Peikert, C. (eds.) CRYPTO 2021, Part IV. LNCS, vol. 12828, pp. 155–178. Springer, Heidelberg (2021). https://doi.org/10.1007/978-3-030-84259-8_6
Acknowledgements
This work was supported in part by the European Union Horizon 2020 ERC Programme (Grant Agreement no. 966570 – CryptAnalytics), the Beyond5G project and the French ANR Project ANR-19-CE39-0011 PRESTO.
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Nguyen, K., Phan, D.H., Pointcheval, D. (2022). Multi-Client Functional Encryption with Fine-Grained Access Control. In: Agrawal, S., Lin, D. (eds) Advances in Cryptology – ASIACRYPT 2022. ASIACRYPT 2022. Lecture Notes in Computer Science, vol 13791. Springer, Cham. https://doi.org/10.1007/978-3-031-22963-3_4
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