Cryptanalysis of Round-Reduced \(\mathtt{LED}\)

Conference paper

DOI: 10.1007/978-3-662-43933-3_7

Volume 8424 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Nikolić I., Wang L., Wu S. (2014) Cryptanalysis of Round-Reduced \(\mathtt{LED}\). In: Moriai S. (eds) Fast Software Encryption. FSE 2013. Lecture Notes in Computer Science, vol 8424. Springer, Berlin, Heidelberg

Abstract

In this paper we present known-plaintext single-key and chosen-key attacks on round-reduced LED-64 and LED-128. We show that with an application of the recently proposed slidex attacks [5], one immediately improves the complexity of the previous single-key 4-step attack on LED-128. Further, we explore the possibility of multicollisions and show single-key attacks on 6 steps of LED-128. A generalization of our multicollision attack leads to the statement that no 6-round cipher with two subkeys that alternate, or 2-round cipher with linearly dependent subkeys, is secure in the single-key model. Next, we exploit the possibility of finding pairs of inputs that follow a certain differential rather than a differential characteristic, and obtain chosen-key differential distinguishers for 5-step LED-64, as well as 8-step and 9-step LED-128. We provide examples of inputs that follow the 8-step differential, i.e. we are able to practically confirm our results on 2/3 of the steps of LED-128. We introduce a new type of chosen-key differential distinguisher, called random-difference distinguisher, and successfully penetrate 10 of the total 12 steps of LED-128. We show that this type of attack is generic in the chosen-key model, and can be applied to any 10-round cipher with two alternating subkeys.

Keywords

LED Lightweight Multicollision Single-key attack Chosen-key attack 

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Division of Mathematical Sciences, School of Physical and Mathematical SciencesNanyang Technological UniversitySingaporeSingapore