Abstract
The understanding of directionality for updatable encryption (UE) schemes is important, but not yet completed in the literature. We show that security in the backward-leak uni-directional key updates setting is equivalent to the no-directional one. Combining with the work of Jiang (ASIACRYPT 2020) and Nishimaki (PKC 2022), it is showed that the backward-leak notion is the strongest one among all known key update notions and more relevant in practice. We propose two novel generic constructions of UE schemes that are secure in the backward-leak uni-directional key update setting from public key encryption (PKE) schemes: the first one requires a key and message homomorphic PKE scheme and the second one requires a bootstrappable PKE scheme. These PKE can be constructed based on standard assumptions (such as the Decisional Diffie-Hellman and Learning With Errors assumptions).
Y. Jiang Galteland—Her work has been co-funded by the IKTPLUSS program of the Research Council of Norway under the scope of and as part of the outcome from the research project Reinforcing the Health Data Infrastructure in Mobility and Assurance through Data Democratization (Health Democratization, 2019–2024, Project No. 288856.
J. Pan—His work is supported by the Research Council of Norway under Project No. 324235.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
Notes
- 1.
- 2.
except for some end epoch \(\textsf{e} _\textsf{end}\), if \(\textsf{e} _\textsf{exp}\le \textsf{e} _\textsf{end}\).
- 3.
A challenge-equal ciphertext is either a challenge ciphertext or an updated ciphertext of the challenge ciphertext.
References
Alamati, N., Montgomery, H., Patranabis, S.: Symmetric primitives with structured secrets. In: Boldyreva, A., Micciancio, D. (eds.) CRYPTO 2019. LNCS, vol. 11692, pp. 650–679. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-26948-7_23
Boneh, D., Eskandarian, S., Kim, S., Shih, M.: Improving speed and security in updatable encryption schemes. In: Moriai, S., Wang, H. (eds.) ASIACRYPT 2020. LNCS, vol. 12493, pp. 559–589. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-64840-4_19
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
Boyd, C., Davies, G.T., Gjøsteen, K., Jiang, Y.: Fast and Secure updatable encryption. In: Micciancio, D., Ristenpart, T. (eds.) CRYPTO 2020. LNCS, vol. 12170, pp. 464–493. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-56784-2_16
Chen, L., Li, Y., Tang, Q.: CCA updatable encryption against malicious re-encryption attacks. In: Moriai, S., Wang, H. (eds.) ASIACRYPT 2020. LNCS, vol. 12493, pp. 590–620. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-64840-4_20
Everspaugh, A., Paterson, K., Ristenpart, T., Scott, S.: Key rotation for authenticated encryption. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017. LNCS, vol. 10403, pp. 98–129. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63697-9_4
Galteland, Y.J., Pan, J.: Backward-leak UNI-directional updatable encryption from (homomorphic) public key encryption. Cryptology ePrint Archive, Paper 2022/324 (2022). https://eprint.iacr.org/2022/324
Gentry, C.: A fully homomorphic encryption scheme. Ph.D. thesis, Stanford, CA, USA (2009)
Jiang, Y.: The direction of updatable encryption does not matter much. In: Moriai, S., Wang, H. (eds.) ASIACRYPT 2020. LNCS, vol. 12493, pp. 529–558. Springer, Cham (2020). https://doi.org/10.1007/978-3-030-64840-4_18
Jiang, Y.: The direction of updatable encryption does not matter much. Cryptology ePrint Archive, Report 2020/622 (2020). https://ia.cr/2020/622
Klooß, M., Lehmann, A., Rupp, A.: (R)CCA secure updatable encryption with integrity protection. In: Ishai, Y., Rijmen, V. (eds.) EUROCRYPT 2019. LNCS, vol. 11476, pp. 68–99. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-17653-2_3
Lehmann, A., Tackmann, B.: Updatable encryption with post-compromise security. In: Nielsen, J.B., Rijmen, V. (eds.) EUROCRYPT 2018. LNCS, vol. 10822, pp. 685–716. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-78372-7_22
Miao, P., Patranabis, S., Watson, G.: Unidirectional updatable encryption and proxy re-encryption from DDH or LWE. Cryptology ePrint Archive, Report 2022/311 (2022). https://ia.cr/2022/311
Nishimaki, R.: The direction of updatable encryption does matter. In: Hanaoka, G., Shikata, J., Watanabe, Y. (eds.) PKC 2022. LNCS, vol. 13178, pp. 194–224. Springer, Cham (2022). https://doi.org/10.1007/978-3-030-97131-1_7
Regev, O.: On lattices, learning with errors, random linear codes, and cryptography. In: Gabow, H.N., Fagin, R. (eds.) 2005 Proceedings of the 37th Annual ACM Symposium on Theory of Computing, pp. 84–93. ACM (2005). https://doi.org/10.1145/1060590.1060603
Slamanig, D., Striecks, C.: Puncture ’em all: Stronger updatable encryption with no-directional key updates. IACR Cryptol. ePrint Arch. 268 (2021). https://eprint.iacr.org/2021/268
Acknowledgements
We thank the anonymous reviewers of Eurocrypt 2022, Crypto 2022, and PKC 2023 for their useful comments. We also thank Christoph Striecks and Daniel Slamanig for their valuable suggestions to improve the previous version of our paper.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2023 International Association for Cryptologic Research
About this paper
Cite this paper
Jiang Galteland, Y., Pan, J. (2023). Backward-Leak Uni-Directional Updatable Encryption from (Homomorphic) Public Key Encryption. In: Boldyreva, A., Kolesnikov, V. (eds) Public-Key Cryptography – PKC 2023. PKC 2023. Lecture Notes in Computer Science, vol 13941. Springer, Cham. https://doi.org/10.1007/978-3-031-31371-4_14
Download citation
DOI: https://doi.org/10.1007/978-3-031-31371-4_14
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-031-31370-7
Online ISBN: 978-3-031-31371-4
eBook Packages: Computer ScienceComputer Science (R0)