Abstract
We study secure multi-party computation (MPC) protocols for branching circuits that contain multiple sub-circuits (i.e., branches) and the output of the circuit is that of single “active” branch. Crucially, the identity of the active branch must remain hidden from the protocol participants.
While such circuits can be securely computed by evaluating each branch and then multiplexing the output, such an approach incurs a communication cost linear in the size of the entire circuit. To alleviate this, a series of recent works have investigated the problem of reducing the communication cost of branching executions inside MPC (without relying on fully homomorphic encryption). Most notably, the stacked garbling paradigm [Heath and Kolesnikov, CRYPTO’20] yields garbled circuits for branching circuits whose size only depends on the size of the largest branch. Presently, however, it is not known how to obtain similar communication improvements for secure computation involving more than two parties.
In this work, we provide a generic framework for branching multi-party computation that supports any number of parties. The communication complexity of our scheme is proportional to the size of the largest branch and the computation is linear in the size of the entire circuit. We provide an implementation and benchmarks to demonstrate practicality of our approach.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Notes
- 1.
We require the underlying MPC to be such that it evaluates the circuit in a gate-by-gate manner and maintains an invariant that for every intermediate wire in the circuit, the parties collectively hold a sharing of the value induced on that wire during evaluation.
- 2.
Our compiler can work with circuits that have gates with arbitrary fan-out. In our construction, it suffices to view such gates as having a single outgoing wire that acts as the incoming wire for multiple gates. Hence, we only assign a single label to the outgoing wire of each gate.
- 3.
Since the type of each gate in each branch is sampled uniformly at random.
- 4.
It grows slightly, since the unary representation of the selection wire must be shared/computed. However the computation of the branch completely dominates the communication.
References
Lattigo v2.2.0. Online: http://github.com/ldsec/lattigo, July 2021. EPFL-LDS
Beaver, D., Micali, S., Rogaway, P.: The round complexity of secure protocols (extended abstract). In: 22nd ACM STOC, pp. 503–513. ACM Press, May 1990
Beck, G., Goel, A., Jain, A., Kaptchuk, G.: Order-C secure multiparty computation for highly repetitive circuits. In: Canteaut, A., Standaert, F.-X. (eds.) EUROCRYPT 2021. LNCS, vol. 12697, pp. 663–693. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-77886-6_23
Ben-Efraim, A., Lindell, Y., Omri, E.: Efficient scalable constant-round MPC via garbled circuits. In: Takagi, T., Peyrin, T. (eds.) ASIACRYPT 2017. LNCS, vol. 10625, pp. 471–498. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-70697-9_17
Ben-Or, M., Goldwasser, S., Wigderson, A.: Completeness theorems for non-cryptographic fault-tolerant distributed computation (extended abstract). In: 20th ACM STOC, pp. 1–10. ACM Press, May 1988
Boneh, D., Lewi, K., Montgomery, H., Raghunathan, A.: Key homomorphic PRFs and their applications. In: Canetti, R., Garay, J.A. (eds.) CRYPTO 2013. LNCS, vol. 8042, pp. 410–428. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40041-4_23
Boyle, E., Gilboa, N., Ishai, Y.: Breaking the circuit size barrier for secure computation under DDH. In: Robshaw, M., Katz, J. (eds.) CRYPTO 2016. LNCS, vol. 9814, pp. 509–539. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53018-4_19
Castagnos, G., Laguillaumie, F.: Linearly homomorphic encryption from \(\sf DDH\). In: Nyberg, K. (ed.) CT-RSA 2015. LNCS, vol. 9048, pp. 487–505. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-16715-2_26
Chaum, D., Crépeau, C., Damgård, I.: Multiparty unconditionally secure protocols (Abstract). In: Pomerance, C. (ed.) CRYPTO 1987. LNCS, vol. 293, p. 462. Springer, Heidelberg (1988). https://doi.org/10.1007/3-540-48184-2_43
Chen, M., et al.: Diogenes: lightweight scalable RSA modulus generation with a dishonest majority. Cryptology ePrint Archive, Report 2020/374 (2020). https://eprint.iacr.org/2020/374
Chida, K., et al.: Fast large-scale honest-majority MPC for malicious adversaries. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018. LNCS, vol. 10993, pp. 34–64. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96878-0_2
Cramer, R., Damgård, I., Escudero, D., Scholl, P., Xing, C.: SPDZ2k: efficient MPC mod \(2^k\) for dishonest majority. Cryptology ePrint Archive, Report 2018/482 (2018). https://eprint.iacr.org/2018/482
Cramer, R., Damgård, I., Nielsen, J.B.: Multiparty computation from threshold homomorphic encryption. In: Pfitzmann, B. (ed.) EUROCRYPT 2001. LNCS, vol. 2045, pp. 280–300. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-44987-6_18
Damgård, I., Ishai, Y.: Constant-round multiparty computation using a black-box pseudorandom generator. In: Shoup, V. (ed.) CRYPTO 2005. LNCS, vol. 3621, pp. 378–394. Springer, Heidelberg (2005). https://doi.org/10.1007/11535218_23
Damgård, I., Jurik, M.: A generalisation, a simplification and some applications of Paillier’s probabilistic public-key system. In: Kim, K. (ed.) PKC 2001. LNCS, vol. 1992, pp. 119–136. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-44586-2_9
Damgård, I., Pastro, V., Smart, N., Zakarias, S.: Multiparty computation from somewhat homomorphic encryption. In: Safavi-Naini, R., Canetti, R. (eds.) CRYPTO 2012. LNCS, vol. 7417, pp. 643–662. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-32009-5_38
Fan, J., Vercauteren, F.: Somewhat practical fully homomorphic encryption. Cryptology ePrint Archive, Report 2012/144 (2012). https://eprint.iacr.org/2012/144
Frederiksen, T.K., Keller, M., Orsini, E., Scholl, P.: A unified approach to MPC with preprocessing using OT. In: Iwata, T., Cheon, J.H. (eds.) ASIACRYPT 2015. LNCS, vol. 9452, pp. 711–735. Springer, Heidelberg (2015). https://doi.org/10.1007/978-3-662-48797-6_29
Gentry, C.: Fully homomorphic encryption using ideal lattices. In: Mitzenmacher, M. (ed.) 41st ACM STOC, pp. 169–178. ACM Press, May/June 2009
Goldreich, O., Micali, S., Wigderson, A.: How to play any mental game or a completeness theorem for protocols with honest majority. In: Aho, A. (ed.) 19th ACM STOC, pp. 218–229. ACM Press, May 1987
Gordon, S.D., Starin, D., Yerukhimovich, A.: The more the merrier: reducing the cost of large scale MPC. In: Canteaut, A., Standaert, F.-X. (eds.) EUROCRYPT 2021. LNCS, vol. 12697, pp. 694–723. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-77886-6_24
Goyal, V., Li, H., Ostrovsky, R., Polychroniadou, A., Song, Y.: ATLAS: efficient and scalable MPC in the honest majority setting. In: Malkin, T., Peikert, C. (eds.) CRYPTO 2021. LNCS, vol. 12826, pp. 244–274. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-84245-1_9
Goyal, V., Polychroniadou, A., Song, Y.: Unconditional communication-efficient MPC via Hall’s marriage theorem. In: Malkin, T., Peikert, C. (eds.) CRYPTO 2021. LNCS, vol. 12826, pp. 275–304. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-84245-1_10
Goyal, V., Song, Y.: Malicious security comes free in honest-majority MPC. Cryptology ePrint Archive, Report 2020/134 (2020). https://eprint.iacr.org/2020/134
Hazay, C., Orsini, E., Scholl, P., Soria-Vazquez, E.: Concretely efficient large-scale MPC with active security (or, TinyKeys for TinyOT). In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018. LNCS, vol. 11274, pp. 86–117. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-03332-3_4
Heath, D., Kolesnikov, V.: Stacked garbling - garbled circuit proportional to longest execution path. In: Micciancio, D., Ristenpart, T. (ed.) CRYPTO 2020, Part II, vol. 12171 of LNCS, pp. 763–792. Springer, Heidelberg, August 2020. https://doi.org/10.1007/978-3-030-56880-1_27
Heath, D., Kolesnikov, V.: \(\sf LogStack\): stacked garbling with \(O(b \log b)\) computation. In: Canteaut, A., François-Xavier Standaert, editors, EUROCRYPT 2021, Part III, volume 12698 of LNCS, pages 3–32. Springer, Heidelberg, October 2021 . https://doi.org/10.1007/978-3-030-77883-5_1
Heath, D., Kolesnikov, V., Peceny, S.: MOTIF: (almost) free branching in GMW - via vector-scalar multiplication. In: Moriai, S., Wang, H. (eds.) ASIACRYPT 2020. Part III, vol. 12493 of LNCS, pp. 3–30. Springer, Heidelberg (2020). https://doi.org/10.1007/978-3-030-64840-4_1
Heath, D., Kolesnikov, V., Peceny, S.: Garbling, stacked and staggered - faster k-out-of-n garbled function evaluation. In: Tibouchi, M., Wang, H. (eds.) Advances in Cryptology - ASIACRYPT 2021 - 27th International Conference on the Theory and Application of Cryptology and Information Security, Singapore, 6–10 December 2021, Proceedings, Part II, vol. 13091 of Lecture Notes in Computer Science, pp. 245–274. Springer (2021). https://doi.org/10.1007/978-3-030-92075-3
Heath, D., Kolesnikov, V., Peceny, S.: Masked triples- amortizing multiplication triples across conditionals. In: Garay, J.A. (ed.) PKC 2021. LNCS, vol. 12711, pp. 319–348. Springer, Cham (2021). https://doi.org/10.1007/978-3-030-75248-4_12
Katz, J., Malka, L.: Constant-round private function evaluation with linear complexity. In: Lee, D.H., Wang, X. (eds.) ASIACRYPT 2011. LNCS, vol. 7073, pp. 556–571. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-25385-0_30
Keller, M.: MP-SPDZ: a versatile framework for multi-party computation. In: Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security (2020)
Keller, M., Orsini, E., Scholl, P.: MASCOT: faster malicious arithmetic secure computation with oblivious transfer. In: Weippl, E.R., Katzenbeisser, S., Kruegel, C., Myers, A.C., Halevi, S. (eds.) ACM CCS 2016, pp. 830–842. ACM Press, October 2016
Keller, M., Pastro, V., Rotaru, D.: Overdrive: making SPDZ great again. In: Nielsen, J.B., Rijmen, V. (eds.) EUROCRYPT 2018. LNCS, vol. 10822, pp. 158–189. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-78372-7_6
Mohassel, P., Sadeghian, S.: How to hide circuits in MPC an efficient framework for private function evaluation. In: Johansson, T., Nguyen, P.Q. (eds.) EUROCRYPT 2013. LNCS, vol. 7881, pp. 557–574. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-38348-9_33
Mohassel, P., Sadeghian, S., Smart, N.P.: Actively secure private function evaluation. In: Sarkar, P., Iwata, T. (eds.) ASIACRYPT 2014. LNCS, vol. 8874, pp. 486–505. Springer, Heidelberg (2014). https://doi.org/10.1007/978-3-662-45608-8_26
Naor, M., Pinkas, B., Reingold, O.: Distributed Pseudo-random functions and KDCs. In: Stern, J. (ed.) EUROCRYPT 1999. LNCS, vol. 1592, pp. 327–346. Springer, Heidelberg (1999). https://doi.org/10.1007/3-540-48910-X_23
Peikert, C., Vaikuntanathan, V., Waters, B.: A framework for efficient and composable oblivious transfer. In: Wagner, D. (ed.) CRYPTO 2008. LNCS, vol. 5157, pp. 554–571. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-85174-5_31
Wails, R., Johnson, A., Starin, D., Yerukhimovich, A., Gordon, S.D.: Stormy: statistics in Tor by measuring securely. In: Cavallaro, L., Kinder, J., Wang, X.F., Katz, J. (eds.) ACM CCS 2019, pp. 615–632. ACM Press, November 2019
Yao, A.C.-C.: How to generate and exchange secrets (extended abstract). In: 27th FOCS, pp. 162–167. IEEE Computer Society Press, October 1986
Acknowledgements
We thank the anonymous reviewers of EUROCRYPT 2022 for their helpful comments. The first, third and forth authors are supported in part by an NSF CNS grant 1814919, NSF CAREER award 1942789 and Johns Hopkins University Catalyst award. The second author is funded by Concordium Blockhain Research Center, Aarhus University, Denmark. The third author is additionally supported by NSF CNS-1653110, NSF CNS-1801479, a Google Security & Privacy Award and DARPA under Agreements No. HR00112020021 and Agreements No. HR001120C0084. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the United States Government or DARPA.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2022 International Association for Cryptologic Research
About this paper
Cite this paper
Goel, A., Hall-Andersen, M., Hegde, A., Jain, A. (2022). Secure Multiparty Computation with Free Branching. In: Dunkelman, O., Dziembowski, S. (eds) Advances in Cryptology – EUROCRYPT 2022. EUROCRYPT 2022. Lecture Notes in Computer Science, vol 13275. Springer, Cham. https://doi.org/10.1007/978-3-031-06944-4_14
Download citation
DOI: https://doi.org/10.1007/978-3-031-06944-4_14
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-031-06943-7
Online ISBN: 978-3-031-06944-4
eBook Packages: Computer ScienceComputer Science (R0)