id: 05918393
dt: a
an: 05918393
au: Jean, Jérémy; Fouque, Pierre-Alain
ti: Practical near-collisions and collisions on round-reduced ECHO-256
    compression function.
so: Joux, Antoine (ed.), Fast software encryption. 18th international workshop,
    FSE 2011, Lyngby, Denmark, February 13‒16, 2011. Revised selected
    papers. Berlin: Springer (ISBN 978-3-642-21701-2/pbk). Lecture Notes in
    Computer Science 6733, 107-127 (2011).
py: 2011
pu: Berlin: Springer
la: EN
cc: 
ut: cryptanalysis; hash functions; SHA-3; ECHO-256; collision attack
ci: 
li: doi:10.1007/978-3-642-21702-9_7
ab: Summary: In this paper, we present new results on the second-round SHA-3
    candidate ECHO. We describe a method to construct a collision in the
    compression function of ECHO-256 reduced to four rounds in $2^{52}$
    operations on AES-columns without significant memory requirements. Our
    attack uses the most recent analyses on ECHO, in particular the
    SuperSBox and SuperMixColumns layers to utilize efficiently the
    available freedom degrees. We also show why some of these results are
    flawed and we propose a solution to fix them. Our work improves the
    time and memory complexity of previous known techniques by using
    available freedom degrees more precisely. Finally, we validate our work
    by an implementation leading to near-collisions in $2^{36}$ operations
    for the 4-round compression function.
rv: