Abstract
In this paper, we describe Oblivious TLS: an MPC protocol that we prove UC secure against a majority of actively corrupted parties. The protocol securely implements TLS 1.3. Thus, any party P who runs TLS can communicate securely with a set of servers running Oblivious TLS; P does not need to modify anything, or even be aware that MPC is used.
Applications of this include communication between servers who offer MPC services and clients, to allow the clients to easily and securely provide inputs or receive outputs. Also, an organization could use Oblivious TLS to improve in-house security while seamlessly connecting to external parties.
Our protocol runs in the preprocessing model, and we did a preliminary non-optimized implementation of the on-line phase. In this version, the hand-shake completes in about 1 s. Based on implementation results from other work, performance of the record protocol using the standard AES-GCM can be expected to achieve an online throughput of about 3 MB/s.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Notes
- 1.
The key derivation function maintains an internal state, therefore all its outputs depend on the Diffie-Hellman secret and the Hello messages.
- 2.
Using the notation of [20, Sect. 7.1], client_handshake_traffic_secret and server_handshake_traffic_secret must not be opened.
- 3.
References
Abram, D.: Oblivious TLS. Master’s thesis, Università degli Studi di Trento, March 2020
Abram, D., Damgård, I., Scholl, P., Trieflinger, S.: Oblivious TLS via multi-party computation. Cryptology ePrint Archive, Report 2021/318 (2021). https://eprint.iacr.org/2021/318
Agrawal, S., Mohassel, P., Mukherjee, P., Rindal, P.: DiSE: distributed symmetric-key encryption. In: ACM CCS 2018. ACM Press, October 2018
Bendlin, R., Damgård, I., Orlandi, C., Zakarias, S.: Semi-homomorphic encryption and multiparty computation. In: Paterson, K.G. (ed.) EUROCRYPT 2011. LNCS, vol. 6632, pp. 169–188. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-20465-4_11
Bernstein, D.J.: Curve25519: new Diffie-Hellman speed records. In: Yung, M., Dodis, Y., Kiayias, A., Malkin, T. (eds.) PKC 2006. LNCS, vol. 3958, pp. 207–228. Springer, Heidelberg (2006). https://doi.org/10.1007/11745853_14
Canetti, R.: Universally composable security: a new paradigm for cryptographic protocols. In: 42nd FOCS. IEEE Computer Society Press, October 2001
Dalskov, A., Orlandi, C., Keller, M., Shrishak, K., Shulman, H.: Securing DNSSEC keys via threshold ECDSA from generic MPC. In: Chen, L., Li, N., Liang, K., Schneider, S. (eds.) ESORICS 2020. LNCS, vol. 12309, pp. 654–673. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-59013-0_32
Damgård, I., Damgård, K., Nielsen, K., Nordholt, P.S., Toft, T.: Confidential benchmarking based on multiparty computation. In: Grossklags, J., Preneel, B. (eds.) FC 2016. LNCS, vol. 9603, pp. 169–187. Springer, Heidelberg (2017). https://doi.org/10.1007/978-3-662-54970-4_10
Damgård, I., Keller, M., Larraia, E., Pastro, V., Scholl, P., Smart, N.P.: Practical covertly secure MPC for dishonest majority – or: breaking the SPDZ limits. In: Crampton, J., Jajodia, S., Mayes, K. (eds.) ESORICS 2013. LNCS, vol. 8134, pp. 1–18. Springer, Heidelberg (2013). https://doi.org/10.1007/978-3-642-40203-6_1
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
Dowling, B., Fischlin, M., Günther, F., Stebila, D.: A cryptographic analysis of the TLS 1.3 handshake protocol. Cryptology ePrint Archive, Report 2020/1044 (2020)
Dworkin, M.: Recommendation for block cipher modes of operation: galois/counter mode (GCM) and GMAC. Technical report (2007)
Furukawa, J., Lindell, Y., Nof, A., Weinstein, O.: High-throughput secure three-party computation for malicious adversaries and an honest majority. In: Coron, J.-S., Nielsen, J.B. (eds.) EUROCRYPT 2017. LNCS, vol. 10211, pp. 225–255. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-56614-6_8
Grassi, L., Rechberger, C., Rotaru, D., Scholl, P., Smart, N.P.: MPC-friendly symmetric key primitives. In: ACM CCS 2016. ACM Press, October 2016
Hazay, C., Scholl, P., Soria-Vazquez, E.: Low cost constant round MPC combining BMR and oblivious transfer. In: Takagi, T., Peyrin, T. (eds.) ASIACRYPT 2017. LNCS, vol. 10624, pp. 598–628. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-70694-8_21
Keller, M., Orsini, E., Rotaru, D., Scholl, P., Soria-Vazquez, E., Vivek, S.: Faster secure multi-party computation of AES and DES using lookup tables. In: Gollmann, D., Miyaji, A., Kikuchi, H. (eds.) ACNS 2017. LNCS, vol. 10355, pp. 229–249. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-61204-1_12
Keller, M., Orsini, E., Scholl, P.: MASCOT: faster malicious arithmetic secure computation with oblivious transfer. In: ACM CCS 2016. ACM Press, October 2016
Krawczyk, H.: Cryptographic extraction and key derivation: the HKDF scheme. In: Rabin, T. (ed.) CRYPTO 2010. LNCS, vol. 6223, pp. 631–648. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-14623-7_34
Nielsen, J.B., Nordholt, P.S., Orlandi, C., Burra, S.S.: A new approach to practical active-secure two-party computation. In: Safavi-Naini, R., Canetti, R. (eds.) CRYPTO 2012. LNCS, vol. 7417, pp. 681–700. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-32009-5_40
Rescorla, E.: The transport layer security (TLS) protocol version 1.3. RFC 8446 (2018)
Rotaru, D., Smart, N.P., Stam, M.: Modes of operation suitable for computing on encrypted data. IACR Trans. Symm. Cryptol. (3) (2017)
Rotaru, D., Smart, N.P., Tanguy, T., Vercauteren, F., Wood, T.: Actively secure setup for SPDZ. Cryptology ePrint Archive, Report 2019/1300 (2019). https://eprint.iacr.org/2019/1300
Zhang, F., Maram, D., Malvai, H., Goldfeder, S., Juels, A.: DECO: liberating web data using decentralized Oracles for TLS. In: Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security (2020)
Acknowledgements
We would like to thank Douglas Stebila and the anonymous reviewers for valuable feedback which helped to improve the paper, as well as Roberto Zunino for suggestions and comments on Damiano Abram’s master’s thesis. The work of Sven Trieflinger and Damiano Abram was funded by Robert Bosch GmbH. Ivan Damgård was supported by the European Research Council (ERC) under the European Unions’s Horizon 2020 research and innovation programme under grant agreement No 669255 (MPCPRO). Peter Scholl was supported by a starting grant from the Aarhus University Research Foundation.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2021 Springer Nature Switzerland AG
About this paper
Cite this paper
Abram, D., Damgård, I., Scholl, P., Trieflinger, S. (2021). Oblivious TLS via Multi-party Computation. In: Paterson, K.G. (eds) Topics in Cryptology – CT-RSA 2021. CT-RSA 2021. Lecture Notes in Computer Science(), vol 12704. Springer, Cham. https://doi.org/10.1007/978-3-030-75539-3_3
Download citation
DOI: https://doi.org/10.1007/978-3-030-75539-3_3
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-75538-6
Online ISBN: 978-3-030-75539-3
eBook Packages: Computer ScienceComputer Science (R0)