HCTR: A Variable-Input-Length Enciphering Mode

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3822)


This paper proposes a blockcipher mode of operation, HCTR, which is a length-preserving encryption mode. HCTR turns an n-bit blockcipher into a tweakable blockcipher that supports arbitrary variable input length which is no less than n bits. The tweak length of HCTR is fixed and can be zero. We prove that HCTR is a strong tweakable pseudorandom permutation ( \(\widetilde{sprp}\)), when the underlying blockcipher is a strong pseudorandom permutation (sprp). HCTR is shown to be a very efficient mode of operation when some pre-computations are taken into consideration. Arbitrary variable input length brings much flexibility in various application environments. HCTR can be used in disk sector encryption, and other length-preserving encryptions, especially for the message that is not multiple of n bits.


Blockcipher tweakable blockcipher disk sector encryption modes of operation symmetric encryption 


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  1. 1.
    Bellare, M., Rogaway, P.: On the construction of variable-input-length ciphers. In: Knudsen, L.R. (ed.) FSE 1999. LNCS, vol. 1636, pp. 231–244. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  2. 2.
    Bellare, M., Rogaway, P.: The game-playing technique. Cryptology ePrint Archive, Report 2004/331 (2004),
  3. 3.
    Black, J., Rogaway, P.: A block-cipher mode of operation for parallelizable message authentication. In: Knudsen, L.R. (ed.) EUROCRYPT 2002. LNCS, vol. 2332, pp. 384–397. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  4. 4.
    Carter, J.L., Wegman, M.N.: Universal classes of hash functions. Journal of Computer and System Sciences 18(2), 143–154 (1979)zbMATHCrossRefMathSciNetGoogle Scholar
  5. 5.
    Crowley, P.: Mercy: A fast large block cipher for disk sector encryption. In: Schneier, B. (ed.) FSE 2000. LNCS, vol. 1978, pp. 49–63. Springer, Heidelberg (2001)CrossRefGoogle Scholar
  6. 6.
    FIPS-197. Federal information processing standards publication (FIPS 197). Advanced Encryption Standard, AES (2001),
  7. 7.
    Fluhrer, S.R.: Cryptanalysis of the mercy block cipher. In: Matsui, M. (ed.) FSE 2001. LNCS, vol. 2355, pp. 28–36. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  8. 8.
    Halevi, S., Rogaway, P.: A tweakable enciphering mode. In: Boneh, D. (ed.) CRYPTO 2003. LNCS, vol. 2729, pp. 482–499. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  9. 9.
    Halevi, S., Rogaway, P.: A parallelizable enciphering mode. In: Okamoto, T. (ed.) CT-RSA 2004. LNCS, vol. 2964, pp. 292–304. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  10. 10.
    Kilian, J., Rogaway, P.: How to protect DES against exhaustive key search. In: Koblitz, N. (ed.) CRYPTO 1996. LNCS, vol. 1109, pp. 252–267. Springer, Heidelberg (1996)Google Scholar
  11. 11.
    Liskov, M., Rivest, R.L., Wagner, D.: Tweakable block ciphers. In: Yung, M. (ed.) CRYPTO 2002. LNCS, vol. 2442, pp. 31–46. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  12. 12.
    Luby, M., Rackoff, C.: How to construct pseudorandom permutations from pseudorandom functions. SIAM Journal on Computing 17(2), 373–386 (1988) (Special issue on cryptography)zbMATHCrossRefMathSciNetGoogle Scholar
  13. 13.
    McGrew, D.A., Fluhrer, S.R.: The extended codebook (XCB) mode of operation. Cryptology ePrint Archive, Report 2004/278 (2004),
  14. 14.
    McGrew, D.A., Viega, J.: The security and performance of the galois/Counter mode (GCM) of operation. In: Canteaut, A., Viswanathan, K. (eds.) INDOCRYPT 2004. LNCS, vol. 3348, pp. 343–355. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  15. 15.
    McGrew, D.A., Viega, J.: The ABL mode of operation (2004),
  16. 16.
    McGrew, D.A., Viega, J.: The galois/counter mode of operation, GCM (2004),
  17. 17.
    Naor, M., Reingold, O.: A pseudo-random encryption mode,
  18. 18.
    Naor, M., Reingold, O.: On the construction of pseudo-random permutations: Luby-rackoff revisited. In: Proceedings of the 29th Annual ACM Symposium on the Theory of Computing (STOC 1997), New York, pp. 189–199 (1997) (Association for Computing Machinery)Google Scholar
  19. 19.
    P1619. IEEE Security in Storage Working Group,
  20. 20.
    Patel, S., Ramzan, Z., Sundaram, G.S.: Towards making luby-rackoff ciphers optimal and practical. In: Knudsen, L.R. (ed.) FSE 1999. LNCS, vol. 1636, pp. 171–185. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  21. 21.
    Patel, S., Ramzan, Z., Sundaram, G.S.: Efficient constructions of variable-input-length block ciphers. In: Handschuh, H., Hasan, M.A. (eds.) SAC 2004. LNCS, vol. 3357, pp. 326–340. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  22. 22.
    Rogaway, P.: Efficient instantiations of tweakable blockciphers and refinements to modes OCB and PMAC. In: Lee, P.J. (ed.) ASIACRYPT 2004. LNCS, vol. 3329, pp. 16–31. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  23. 23.
    Rogaway, P., Bellare, M., Black, J., Krovetz, T.: OCB: a block-cipher mode of operation for efficient authenticated encryptiona. In: Proceedings of the 8th ACM Conference on Computer and Communications Security, pp. 196–205 (2001)Google Scholar
  24. 24.
    Schroeppel, R.: The hasty pudding cipher,
  25. 25.
    Shoup, V.: On fast and provably secure message authentication based on universal hashing. In: Koblitz, N. (ed.) CRYPTO 1996. LNCS, vol. 1109, pp. 313–328. Springer, Heidelberg (1996)Google Scholar
  26. 26.
    Shoup, V.: Sequences of games: a tool for taming complexity in security proofs. Cryptology ePrint Archive, Report 2004/332 (2004),
  27. 27.
    SP-800-38A. Recommendation for block cipher modes of operation - methods and techniques. NIST Special Publication 800-38A (2001),

Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  1. 1.State Key Laboratory of Information SecurityGraduate School of Chinese Academy of SciencesBeijingChina
  2. 2.State Key Laboratory of Information SecurityInstitution of Software of Chinese Academy of SciencesBeijingChina

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