A General Formulation of Algebraic and Fast Correlation Attacks Based on Dedicated Sample Decimation

Author(s):  
Miodrag J. Mihaljević ◽  
Marc P. C. Fossorier ◽  
Hideki Imai
Author(s):  
Bin Zhang ◽  
Xinxin Gong ◽  
Willi Meier

In this paper, we study the security of Grain-like small state stream ciphers by fast correlation attacks, which are commonly regarded as classical cryptanalytic methods against LFSR-based stream ciphers. We extend the cascaded structure adopted in such primitives in general and show how to restore the full internal state part-by-part if the non-linear combining function meets some characteristic. As a case study, we present a key recovery attack against Fruit, a tweaked version of Sprout that employs key-dependent state updating in the keystream generation phase. Our attack requires 262.8 Fruit encryptions and 222.3 keystream bits to determine the 80-bit secret key. Practical simulations on a small-scale version confirmed our results.


2012 ◽  
Vol 4 (3-4) ◽  
pp. 173-202 ◽  
Author(s):  
Martin Ågren ◽  
Carl Löndahl ◽  
Martin Hell ◽  
Thomas Johansson

Sign in / Sign up

Export Citation Format

Share Document