Skip to main content

Registration-Based Encryption from Standard Assumptions

  • Conference paper
  • First Online:
Public-Key Cryptography – PKC 2019 (PKC 2019)

Part of the book series: Lecture Notes in Computer Science ((LNSC,volume 11443))

Included in the following conference series:

Abstract

The notion of Registration-Based Encryption (RBE) was recently introduced by Garg, Hajiabadi, Mahmoody, and Rahimi [TCC’18] with the goal of removing the private-key generator (PKG) from IBE. Specifically, RBE allows encrypting to identities using a (compact) master public key, like how IBE is used, with the benefit that the PKG is substituted with a weaker entity called “key curator” who has no knowledge of any secret keys. Here individuals generate their secret keys on their own and then publicly register their identities and their corresponding public keys to the key curator. Finally, individuals obtain “rare” decryption-key updates from the key curator as the population grows. In their work, they gave a construction of RBE schemes based on the combination of indistinguishability obfuscation and somewhere statistically binding hash functions. However, they left open the problem of constructing RBE schemes based on standard assumptions.

In this work, we resolve the above problem and construct RBE schemes based on standard assumptions (e.g., CDH or LWE). Furthermore, we show a new application of RBE in a novel context. In particular, we show that anonymous variants of RBE (which we also construct under standard assumptions) can be used for realizing abstracts forms of anonymous messaging tasks in simple scenarios in which the parties communicate by writing messages on a shared board in a synchronized way.

S. Garg—Research supported in part from DARPA/ARL SAFEWARE Award W911NF15C0210, AFOSR Award FA9550-15-1-0274, AFOSR YIP Award, DARPA and SPAWAR under contract N66001-15-C-4065, a Hellman Award and research grants by the Okawa Foundation, Visa Inc., and Center for Long-Term Cybersecurity (CLTC, UC Berkeley). The views expressed are those of the author and do not reflect the official policy or position of the funding agencies.

M. Hajiabadi—Supported by NSF award CCF-1350939 and AFOSR Award FA9550-15-1-0274.

M. Mahmoody—Supported by NSF CAREER award CCF-1350939, and two University of Virginia’s SEAS Research Innovation Awards.

A. Rahimi—Supported by NSF award CCF-1350939.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 79.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 99.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    This will guarantee that the leaf nodes are sorted in ascending order of the timestamps of the identities.

  2. 2.

    Looking ahead, we need to store the root hashes of \(\mathsf {TimeTree}\) at mulitple times in order to ensure that the number of updates required by each person remains \(\log n\).

  3. 3.

    The main advantage of having a Red-Black Merkle tree is that after each insertion, the depth of the tree does not increase beyond \(\log n\), where n is the number of people registered in the system. The balancing is not perfect, but ensures that further insertions, rearrangement after insertion to balance, searches, all take time \(O(\log n)\).

  4. 4.

    Note that we must store the versions of the same \(\mathsf {TimeTree}\) at times corresponding to last updation of each \(\mathsf {Tree}_i\) in \(\mathcal {T}\). But there would only be \(\log n\) such versions.

  5. 5.

    Alternately, we could have performed these operations for each i, which would be the number of trees in \(\mathcal {T}\). Here, we would have obtained a value \(\ne \bot \) only for one i.

References

  1. Al-Riyami, S.S., Paterson, K.G.: Certificateless public key cryptography. In: Laih, C.-S. (ed.) ASIACRYPT 2003. LNCS, vol. 2894, pp. 452–473. Springer, Heidelberg (2003). https://doi.org/10.1007/978-3-540-40061-5_29

    Chapter  Google Scholar 

  2. Alexopoulos, N., Kiayias, A., Talviste, R., Zacharias, T.: MCMix: anonymous messaging via secure multiparty computation. In: USENIX Security Symposium, pp. 1217–1234. USENIX Association, Vancouver (2017)

    Google Scholar 

  3. Barak, B., et al.: On the (im)possibility of obfuscating programs. In: Kilian, J. (ed.) CRYPTO 2001. LNCS, vol. 2139, pp. 1–18. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-44647-8_1

    Chapter  Google Scholar 

  4. Bellare, M., Boldyreva, A., Desai, A., Pointcheval, D.: Key-privacy in public-key encryption. In: Boyd, C. (ed.) ASIACRYPT 2001. LNCS, vol. 2248, pp. 566–582. Springer, Heidelberg (2001). https://doi.org/10.1007/3-540-45682-1_33

    Chapter  MATH  Google Scholar 

  5. Bellare, M., Singh, A.C., Jaeger, J., Nyayapati, M., Stepanovs, I.: Ratcheted encryption and key exchange: the security of messaging. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017. LNCS, vol. 10403, pp. 619–650. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63697-9_21

    Chapter  Google Scholar 

  6. Boneh, D., Di Crescenzo, G., Ostrovsky, R., Persiano, G.: Public key encryption with keyword search. In: Cachin, C., Camenisch, J.L. (eds.) EUROCRYPT 2004. LNCS, vol. 3027, pp. 506–522. Springer, Heidelberg (2004). https://doi.org/10.1007/978-3-540-24676-3_30

    Chapter  Google Scholar 

  7. Boneh, D., Franklin, M.: 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

    Chapter  Google Scholar 

  8. Borisov, N., Goldberg, I., Brewer, E.: Off-the-record communication, or, why not to use PGP. In: Proceedings of the 2004 ACM Workshop on Privacy in the Electronic Society, pp. 77–84. ACM (2004)

    Google Scholar 

  9. Boyen, X., Waters, B.: Anonymous hierarchical identity-based encryption (without random oracles). In: Dwork, C. (ed.) CRYPTO 2006. LNCS, vol. 4117, pp. 290–307. Springer, Heidelberg (2006). https://doi.org/10.1007/11818175_17

    Chapter  Google Scholar 

  10. Brakerski, Z., Lombardi, A., Segev, G., Vaikuntanathan, V.: Anonymous IBE, leakage resilience and circular security from new assumptions. In: Nielsen, J.B., Rijmen, V. (eds.) EUROCRYPT 2018, Part I. LNCS, vol. 10820, pp. 535–564. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-78381-9_20

    Chapter  Google Scholar 

  11. Callas, J.: Identity-based encryption with conventional public-key infrastructure (2005)

    Google Scholar 

  12. Cheng, Z., Comley, R., Vasiu, L.: Remove key escrow from the identity-based encryption system. In: Levy, J.-J., Mayr, E.W., Mitchell, J.C. (eds.) TCS 2004. IIFIP, vol. 155, pp. 37–50. Springer, Boston, MA (2004). https://doi.org/10.1007/1-4020-8141-3_6

    Chapter  Google Scholar 

  13. Cho, C., Döttling, N., Garg, S., Gupta, D., Miao, P., Polychroniadou, A.: Laconic oblivious transfer and its applications. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017, Part II. LNCS, vol. 10402, pp. 33–65. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63715-0_2

    Chapter  Google Scholar 

  14. Chow, S.S.M.: Removing escrow from identity-based encryption. In: Jarecki, S., Tsudik, G. (eds.) PKC 2009. LNCS, vol. 5443, pp. 256–276. Springer, Heidelberg (2009). https://doi.org/10.1007/978-3-642-00468-1_15

    Chapter  Google Scholar 

  15. Cohn-Gordon, K., Cremers, C., Dowling, B., Garratt, L., Stebila, D.: A formal security analysis of the signal messaging protocol. In: 2017 IEEE European Symposium on Security and Privacy (EuroS&P), pp. 451–466. IEEE (2017)

    Google Scholar 

  16. Cooper, D.A., Birman, K.P.: Preserving privacy in a network of mobile computers. Technical report, Cornell University (1995)

    Google Scholar 

  17. Corrigan-Gibbs, H., Boneh, D., Mazières, D.: Riposte: an anonymous messaging system handling millions of users. arXiv:1503.06115 (2015)

  18. Corrigan-Gibbs, H., Ford, B.: Dissent: accountable anonymous group messaging. In: Proceedings of the 17th ACM Conference on Computer and Communications Security, pp. 340–350. ACM (2010)

    Google Scholar 

  19. Döttling, N., Garg, S.: Identity-based encryption from the Diffie-Hellman assumption. In: Katz, J., Shacham, H. (eds.) CRYPTO 2017, Part I. LNCS, vol. 10401, pp. 537–569. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-63688-7_18

    Chapter  Google Scholar 

  20. Döttling, N., Garg, S., Hajiabadi, M., Masny, D.: New constructions of identity-based and key-dependent message secure encryption schemes. In: Abdalla, M., Dahab, R. (eds.) PKC 2018, Part I. LNCS, vol. 10769, pp. 3–31. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-76578-5_1

    Chapter  MATH  Google Scholar 

  21. Garg, S., Gentry, C., Halevi, S., Raykova, M., Sahai, A., Waters, B.: Candidate indistinguishability obfuscation and functional encryption for all circuits. In: 54th Annual Symposium on Foundations of Computer Science, Berkeley, CA, USA, 26–29 October 2013, pp. 40–49. IEEE Computer Society Press (2013)

    Google Scholar 

  22. Garg, S., Hajiabadi, M., Mahmoody, M., Rahimi, A.: Registration-based encryption: removing private-key generator from IBE. In: Beimel, A., Dziembowski, S. (eds.) TCC 2018. LNCS, vol. 11239, pp. 689–718. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-03807-6_25

    Chapter  Google Scholar 

  23. Goyal, V.: Reducing trust in the PKG in identity based cryptosystems. In: Menezes, A. (ed.) CRYPTO 2007. LNCS, vol. 4622, pp. 430–447. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-74143-5_24

    Chapter  Google Scholar 

  24. Goyal, V., Lu, S., Sahai, A., Waters, B.: Black-box accountable authority identity-based encryption. In: Proceedings of the 15th ACM Conference on Computer and Communications Security, pp. 427–436. ACM (2008)

    Google Scholar 

  25. Hubacek, P., Wichs, D.: On the communication complexity of secure function evaluation with long output. In: Roughgarden, T. (ed.) ITCS 2015: 6th Conference on Innovations in Theoretical Computer Science, Rehovot, Israel, 11–13 January 2015, pp. 163–172. Association for Computing Machinery (2015)

    Google Scholar 

  26. Jaeger, J., Stepanovs, I.: Optimal channel security against fine-grained state compromise: the safety of messaging. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018. LNCS, vol. 10991, pp. 33–62. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96884-1_2

    Chapter  Google Scholar 

  27. Mohassel, P.: A closer look at anonymity and robustness in encryption schemes. In: Abe, M. (ed.) ASIACRYPT 2010. LNCS, vol. 6477, pp. 501–518. Springer, Heidelberg (2010). https://doi.org/10.1007/978-3-642-17373-8_29

    Chapter  MATH  Google Scholar 

  28. Poettering, B., Rösler, P.: Towards bidirectional ratcheted key exchange. In: Shacham, H., Boldyreva, A. (eds.) CRYPTO 2018. LNCS, vol. 10991, pp. 3–32. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-96884-1_1

    Chapter  Google Scholar 

  29. Rogaway, P.: The moral character of cryptographic work. IACR Cryptology ePrint Archive 2015:1162 (2015)

    Google Scholar 

  30. Rösler, P., Mainka, C., Schwenk, J.: More is less: on the end-to-end security of group chats in signal, WhatsApp, and Threema (2018)

    Google Scholar 

  31. Shamir, A.: Identity-based cryptosystems and signature schemes. In: Blakley, G.R., Chaum, D. (eds.) CRYPTO 1984. LNCS, vol. 196, pp. 47–53. Springer, Heidelberg (1985). https://doi.org/10.1007/3-540-39568-7_5

    Chapter  Google Scholar 

  32. Unger, N., et al.: SoK: secure messaging. In: 2015 IEEE Symposium on Security and Privacy (SP), pp. 232–249. IEEE (2015)

    Google Scholar 

  33. Wei, Q., Qi, F., Tang, Z.: Remove key escrow from the BF and Gentry identity-based encryption with non-interactive key generation. Telecommun. Syst. 69, 253–262 (2018)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Sanjam Garg .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2019 International Association for Cryptologic Research

About this paper

Check for updates. Verify currency and authenticity via CrossMark

Cite this paper

Garg, S., Hajiabadi, M., Mahmoody, M., Rahimi, A., Sekar, S. (2019). Registration-Based Encryption from Standard Assumptions. In: Lin, D., Sako, K. (eds) Public-Key Cryptography – PKC 2019. PKC 2019. Lecture Notes in Computer Science(), vol 11443. Springer, Cham. https://doi.org/10.1007/978-3-030-17259-6_3

Download citation

  • DOI: https://doi.org/10.1007/978-3-030-17259-6_3

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-17258-9

  • Online ISBN: 978-3-030-17259-6

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics