Abstract
Tweakable blockcipher (TBC) is an extension of standard blockcipher introduced by Liskov, Rivest and Wagner in 2002. TBC is a versatile building block for efficient symmetric-key cryptographic functions, such as authenticated encryption.
In this paper we study the problem of extending tweak of a given TBC of fixed-length tweak, which is a variant of popular problem of converting a blockcipher into a TBC, i.e., blockcipher mode of operation. The problem is particularly important for known dedicated TBCs since they have relatively short tweak. We propose a simple and efficient solution, called \(\text {XTX}\), for this problem. \(\text {XTX}\) converts a TBC of fixed-length tweak into another TBC of arbitrarily long tweak, by extending the scheme of Liskov, Rivest and Wagner that converts a blockcipher into a TBC. Given a TBC of n-bit block and m-bit tweak, \(\text {XTX}\) provides \((n+m){/}2\)-bit security while conventional methods provide n / 2 or m / 2-bit security. We also show that \(\text {XTX}\) is even useful when combined with some blockcipher modes for building TBC having security beyond the birthday bound.
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Notes
- 1.
The two schemes shown by [17] are also called LRW1 and LRW2, and we refer to LRW2 throughout this paper.
- 2.
- 3.
- 4.
The name CLRW2 means it is a chain of the second construction of [17], which we simply call LRW.
- 5.
Originally the constant was 6, however an error in the proof was pointed out by Procter [26]. He fixed the proof with an increased constant, 8.
References
CAESAR: Competition for authenticated encryption: security, applicability, and robustness. http://competitions.cr.yp.to/caesar.html/
Skein Hash Function: SHA-3 submission (2008). http://www.skein-hash.info/
Aoki, K., Yasuda, K.: The security and performance of “GCM” when short multiplications are used instead. In: Kutyłowski, M., Yung, M. (eds.) Inscrypt 2012. LNCS, vol. 7763, pp. 225–245. Springer, Heidelberg (2013)
Bellare, M., Desai, A., Jokipii, E., Rogaway, P.: A concrete security treatment of symmetric encryption. In: 38th Annual Symposium on Foundations of Computer Science, FOCS 1997, 19–22 Oct 1997, pp. 394–403. IEEE Computer Society, Miami Beach (1997)
Bellare, M., Krovetz, T., Rogaway, P.: Luby-Rackoff backwards: increasing security by making block ciphers non-invertible. In: Nyberg, K. (ed.) EUROCRYPT 1998. LNCS, vol. 1403, pp. 266–280. Springer, Heidelberg (1998)
Bellare, M., Rogaway, P.: The security of triple encryption and a framework for code-based game-playing proofs. In: Vaudenay, S. (ed.) EUROCRYPT 2006. LNCS, vol. 4004, pp. 409–426. Springer, Heidelberg (2006)
Carter, L., Wegman, M.N.: Universal classes of hash functions. J. Comput. Syst. Sci. 18(2), 143–154 (1979)
Cogliati, B., Lampe, R., Seurin, Y.: Tweaking Even-Mansour ciphers. In: Gennaro, R., Robshaw, M. (eds.) CRYPTO 2015, Part I. LNCS, vol. 9215, pp. 189–208. Springer, Heidelberg (2015). Full version in Cryptology ePrint Archive, Report 2015/539. http://eprint.iacr.org/
Coron, J.-S., Dodis, Y., Mandal, A., Seurin, Y.: A domain extender for the ideal cipher. In: Micciancio, D. (ed.) TCC 2010. LNCS, vol. 5978, pp. 273–289. Springer, Heidelberg (2010)
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)
Even, S., Mansour, Y.: A construction of a cipher from a single pseudorandom permutation. J. Cryptol. 10(3), 151–162 (1997)
Hirose, S., Sasaki, Y., Yasuda, K.: IV-FV authenticated encryption and triplet-robust decryption. In: Early Symetric Crypto, ESC 2015 (2015)
Jean, J., Nikolic, I., Peyrin, T.: Tweaks and keys for block ciphers: the TWEAKEY framework. In: Sarkar, P., Iwata, T. (eds.) ASIACRYPT 2014. LNCS, vol. 8874, pp. 274–288. Springer, Heidelberg (2014)
Jetchev, D., Özen, O., Stam, M.: Understanding adaptivity: random systems revisited. In: Wang, X., Sako, K. (eds.) ASIACRYPT 2012. LNCS, vol. 7658, pp. 313–330. Springer, Heidelberg (2012)
Lampe, R., Seurin, Y.: Tweakable blockciphers with asymptotically optimal security. In: Moriai, S. (ed.) FSE 2013. LNCS, vol. 8424, pp. 133–152. Springer, Heidelberg (2014)
Landecker, W., Shrimpton, T., Terashima, R.S.: Tweakable blockciphers with beyond birthday-bound security. In: Safavi-Naini, R., Canetti, R. (eds.) CRYPTO 2012. LNCS, vol. 7417, pp. 14–30. Springer, Heidelberg (2012)
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)
Maurer, U.M.: Indistinguishability of random systems. In: Knudsen, L.R. (ed.) EUROCRYPT 2002. LNCS, vol. 2332, pp. 110–132. Springer, Heidelberg (2002)
Maurer, U.M., Pietrzak, K.: Composition of random systems: when two weak make one strong. In: Naor, M. (ed.) TCC 2004. LNCS, vol. 2951, pp. 410–427. Springer, Heidelberg (2004)
Mennink, B.: Optimally secure tweakable blockciphers. In: Leander, G. (ed.) FSE 2015. LNCS, vol. 9054, pp. 428–448. Springer, Heidelberg (2015)
Mennink, B.: XPX: generalized tweakable even-mansour with improved security guarantees. IACR Cryptology ePrint Archive 2015, 476 (2015)
Minematsu, K.: Improved security analysis of XEX and LRW modes. In: Biham, E., Youssef, A.M. (eds.) SAC 2006. LNCS, vol. 4356, pp. 96–113. Springer, Heidelberg (2007)
Minematsu, K.: Beyond-birthday-bound security based on tweakable block cipher. In: Dunkelman, O. (ed.) FSE 2009. LNCS, vol. 5665, pp. 308–326. Springer, Heidelberg (2009)
Patarin, J.: The “coefficients H” technique. In: Avanzi, R.M., Keliher, L., Sica, F. (eds.) SAC 2008. LNCS, vol. 5381, pp. 328–345. Springer, Heidelberg (2009)
Pietrzak, K.: Composition does not imply adaptive security. In: Shoup, V. (ed.) CRYPTO 2005. LNCS, vol. 3621, pp. 55–65. Springer, Heidelberg (2005)
Procter, G.: A note on the CLRW2 tweakable block cipher construction. IACR Cryptology ePrint Archive 2014, 111 (2014)
Procter, G., Cid, C.: On weak keys and forgery attacks against polynomial-based MAC schemes. In: Moriai, S. (ed.) FSE 2013. LNCS, vol. 8424, pp. 287–304. Springer, Heidelberg (2014)
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)
Sasaki, Y., Todo, Y., Aoki, K., Naito, Y., Sugawara, T., Murakami, Y., Matsui, M., Hirose, S.: Minalpher. A submission to CAESAR
Schroeppel, R.: Hasty pudding cipher. AES submission (1998). http://www.cs.arizona.edu/rcs/hpc/
Shrimpton, T., Terashima, R.S.: A modular framework for building variable-input-length tweakable ciphers. In: Sako, K., Sarkar, P. (eds.) ASIACRYPT 2013, Part I. LNCS, vol. 8269, pp. 405–423. Springer, Heidelberg (2013)
Acknowledgments
The authors would like to thank the anonymous reviewers for highly constructive and insightful comments. The work by Tetsu Iwata was supported in part by JSPS KAKENHI, Grant-in-Aid for Scientific Research (B), Grant Number 26280045.
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Minematsu, K., Iwata, T. (2015). Tweak-Length Extension for Tweakable Blockciphers. In: Groth, J. (eds) Cryptography and Coding. IMACC 2015. Lecture Notes in Computer Science(), vol 9496. Springer, Cham. https://doi.org/10.1007/978-3-319-27239-9_5
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