Advertisement

Practical Identity-Based Encryption Without Random Oracles

  • Craig Gentry
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4004)

Abstract

We present an Identity Based Encryption (IBE) system that is fully secure in the standard model and has several advantages over previous such systems – namely, computational efficiency, shorter public parameters, and a “tight” security reduction, albeit to a stronger assumption that depends on the number of private key generation queries made by the adversary. Our assumption is a variant of Boneh et al.’s decisional Bilinear Diffie-Hellman Exponent assumption, which has been used to construct efficient hierarchical IBE and broadcast encryption systems. The construction is remarkably simple. It also provides recipient anonymity automatically, providing a second (and more efficient) solution to the problem of achieving anonymous IBE without random oracles. Finally, our proof of CCA2 security, which has more in common with the security proof for the Cramer-Shoup encryption scheme than with security proofs for other IBE systems, may be of independent interest.

Keywords

Identity Based Encryption 

References

  1. 1.
    Abdalla, M., Bellare, M., Catalano, D., Kiltz, E., Kohno, T., Lange, T., Malone-Lee, J., Neven, G., Paillier, P., Shi, H.: Searchable Encryption Revisited: Consistency Properties, Relation to Anonymous IBE, and Extensions. In: Shoup, V. (ed.) CRYPTO 2005. LNCS, vol. 3621, pp. 205–222. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  2. 2.
    Attrapadung, N., Chevallier-Mames, B., Furukawa, J., Gomi, T., Hanaoka, G., Imai, H., Zhang, R.: Efficient Identity Based Encryption with Tight Security Reduction. Cryptology ePrint Archive 2005/320 (2005)Google Scholar
  3. 3.
    Bellare, M., Rogaway, P.: Random Oracles are Practical: A Paradigm for Designing Efficient Protocols. In: Proc. of ACM CCS, pp. 62–73 (1993)Google Scholar
  4. 4.
    Boneh, D., Boyen, X.: Efficient Selective-ID Identity Based Encryption without Random Oracles. In: Cachin, C., Camenisch, J.L. (eds.) EUROCRYPT 2004. LNCS, vol. 3027, pp. 223–238. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  5. 5.
    Boneh, D., Boyen, X.: Secure Identity Based Encryption without Random Oracles. In: Franklin, M. (ed.) CRYPTO 2004. LNCS, vol. 3152, pp. 443–459. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  6. 6.
    Boneh, D., Boyen, X., Goh, E.-J.: Hierarchical Identity Based Encryption with Constant Size Ciphertext. In: Cramer, R.J.F. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 440–456. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  7. 7.
    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)CrossRefGoogle Scholar
  8. 8.
    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)CrossRefGoogle Scholar
  9. 9.
    Boneh, D., Franklin, M.: Identity Based Encryption from the Weil pairing. SIAM Journal of Computing 32(3), 586–615 (2003)MathSciNetCrossRefMATHGoogle Scholar
  10. 10.
    Boneh, D., Gentry, C., Waters, B.: Collusion-Resistant Broadcast Encryption with Short Ciphertexts and Private Keys. In: Shoup, V. (ed.) CRYPTO 2005. LNCS, vol. 3621, pp. 258–275. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  11. 11.
    Boneh, D., Katz, J.: Improved Efficiency for CCA-Secure Cryptosystems Built Using Identity Based Encryption. In: Menezes, A. (ed.) CT-RSA 2005. LNCS, vol. 3376, pp. 87–103. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  12. 12.
    Boneh, D., Lynn, B., Shacham, H.: Short signatures from the Weil pairing. In: Boyd, C. (ed.) ASIACRYPT 2001. LNCS, vol. 2248, pp. 514–532. Springer, Heidelberg (2001)CrossRefGoogle Scholar
  13. 13.
    Boyen, X., Mei, Q., Waters, B.: Direct Chosen Ciphertext Security from Identity Based Techniques. In: Proc. of ACM CCS, pp. 320–329 (2005)Google Scholar
  14. 14.
    Boyen, X., Waters, B.: Anonymous Hierarchical Identity-Based Encryption (without Random Oracles). Cryptology ePrint Archive 2006/085 (2006)Google Scholar
  15. 15.
    Canetti, R., Halevi, S., Katz, J.: A Forward-Secure Public-Key Encryption Scheme. In: Biham, E. (ed.) EUROCRYPT 2003. LNCS, vol. 2656, pp. 255–271. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  16. 16.
    Canetti, R., Halevi, S., Katz, J.: Chosen-Ciphertext Security from Identity-Based Encryption. In: Cachin, C., Camenisch, J.L. (eds.) EUROCRYPT 2004. LNCS, vol. 3027, pp. 207–222. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  17. 17.
    Cramer, R., Shoup, V.: A Practical Public Key Cryptosystem Provably Secure Against Adaptive Chosen Ciphertext Attacks. In: Krawczyk, H. (ed.) CRYPTO 1998. LNCS, vol. 1462, pp. 13–25. Springer, Heidelberg (1998)CrossRefGoogle Scholar
  18. 18.
    Cramer, R., Shoup, V.: Signature Schemes Based on the Strong RSA Assumption. In: Proc. of ACM CCS, pp. 46–51 (1999)Google Scholar
  19. 19.
    Dodis, Y.: Efficient Construction of (Distributed) Verifiable Random Functions. In: Desmedt, Y.G. (ed.) PKC 2003. LNCS, vol. 2567, pp. 1–17. Springer, Heidelberg (2002)Google Scholar
  20. 20.
    Dodis, Y., Yampolskiy, A.: A Verifiable Random Function with Short Proofs and Keys. In: Vaudenay, S. (ed.) PKC 2005. LNCS, vol. 3386, pp. 416–431. Springer, Heidelberg (2005)CrossRefGoogle Scholar
  21. 21.
    Gentry, C., Silverberg, A.: Hierarchical ID-Based Cryptography. In: Zheng, Y. (ed.) ASIACRYPT 2002. LNCS, vol. 2501, pp. 548–566. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  22. 22.
    Horwitz, J., Lynn, B.: Toward Hierarchical Identity-Based Encryption. In: Knudsen, L.R. (ed.) EUROCRYPT 2002. LNCS, vol. 2332, pp. 466–481. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  23. 23.
    Katz, J., Wang, N.: Efficiency Improvements for Signature Schemes with Tight Security Reductions. In: Proc. of ACM CCS, pp. 155–164 (2003)Google Scholar
  24. 24.
    Kurosawa, K., Desmedt, Y.: A New Paradigm of Hybrid Encryption Scheme. In: Franklin, M. (ed.) CRYPTO 2004. LNCS, vol. 3152, pp. 426–442. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  25. 25.
    Shamir, A.: Identity-Based Cryptosystems and Signature Schemes. In: Blakely, G.R., Chaum, D. (eds.) CRYPTO 1984. LNCS, vol. 196, pp. 47–53. Springer, Heidelberg (1985)CrossRefGoogle Scholar
  26. 26.
    Shoup, V.: Lower Bounds for Discrete Logarithms and Related Problems. In: Fumy, W. (ed.) EUROCRYPT 1997. LNCS, vol. 1233, pp. 256–266. Springer, Heidelberg (1997)CrossRefGoogle Scholar
  27. 27.
    Waters, B.: Efficient Identity-Based Encryption without Random Oracles. In: Cramer, R.J.F. (ed.) EUROCRYPT 2005. LNCS, vol. 3494, pp. 114–127. Springer, Heidelberg (2005)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Craig Gentry
    • 1
  1. 1.Stanford UniversityUSA

Personalised recommendations