Cryptanalysis of the stream cipher LEX. Biryukov (The Design of a Stream Cipher LEX, Proceedings of Selected Areas in Cryptography, 2006 Springer, pp 67–75, 2007) presented a new methodology of stream cipher design called leak extraction. The stream cipher LEX, based on this methodology and on the AES block cipher, was selected to round 3 of the eSTREAM competition. The suggested methodology seemed promising, and LEX, due to its elegance, simplicity, and performance, was expected to be selected to the eSTREAM portfolio. In this article we present a key recovery attack on LEX. The attack requires about 240 bytes of key-stream produced by the same key (possibly under many different IVs), and retrieves the secret key in time of about 2100 AES encryptions. Following a preliminary version of our attack, LEX was discarded from the final portfolio of eSTREAM.

References in zbMATH (referenced in 19 articles , 1 standard article )

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  1. Hamann, Matthias; Krause, Matthias; Meier, Willi; Zhang, Bin: Design and analysis of small-state grain-like stream ciphers (2018)
  2. Jean, Jérémy; Nikolić, Ivica: Efficient design strategies based on the \textsfAESround function (2016)
  3. Li, Rongjia; Jin, Chenhui: Meet-in-the-middle attacks on 10-round AES-256 (2016)
  4. Dunkelman, Orr; Keller, Nathan; Shamir, Adi: Improved single-key attacks on 8-round AES-192 and AES-256 (2015)
  5. Dunkelman, Orr; Keller, Nathan: Cryptanalysis of the stream cipher LEX (2013)
  6. Jakimoski, Goce; Khajuria, Samant: ASC-1: an authenticated encryption stream cipher (2012)
  7. Barreto, Paulo; Nikov, Ventzislav; Nikova, Svetla; Rijmen, Vincent; Tischhauser, Elmar: Whirlwind: a new cryptographic hash function (2010)
  8. Huang, Jianyong; Susilo, Willy; Seberry, Jennifer: Differential fault analysis of LEX (2010)
  9. Daemen, Joan; Lamberger, Mario; Pramstaller, Norbert; Rijmen, Vincent; Vercauteren, Frederik: Computational aspects of the expected differential probability of 4-round AES and AES-like ciphers (2009)
  10. Hamburg, Mike: Accelerating AES with vector permute instructions (2009)
  11. Hell, Martin; Johansson, Thomas; Brynielsson, Lennart: An overview of distinguishing attacks on stream ciphers (2009)
  12. Bernstein, Daniel J.; Schwabe, Peter: New AES software speed records (2008)
  13. Biryukov, Alex: Design of a new stream cipher-LEX (2008) ioport
  14. Dunkelman, Orr; Keller, Nathan: A new attack on the LEX stream cipher (2008)
  15. Pieprzyk, Josef (ed.): Advances in cryptology -- ASIACRYPT 2008. 14th international conference on the theory and application of cryptology and information security, Melbourne, Australia, December 7--11, 2008. Proceedings (2008)
  16. Biham, Eli (ed.); Youssef, Amr M. (ed.): Selected areas in cryptography. 13th international workshop, SAC 2006, Montreal, Canada, August 17--18, 2006. Revised selected papers. (2007)
  17. Biryukov, Alex: The design of a stream cipher LEX (2007)
  18. Robshaw, Matthew (ed.): Fast software encryption. 13th international workshop, FSE 2006, Graz, Austria, March 15--17, 2006. Revised selected papers. (2006)
  19. Wu, Hongjun; Preneel, Bart: Resynchronization attacks on WG and LEX (2006)