In May 2012, a highly advanced malware for espionage dubbed Flame was found targeting the Middle-East. As it turned out, it used a forged signature to infect Windows machines by MITM-ing Windows Update. Using counter-cryptanalysis, Stevens found that the forged signature was made possible by a chosen-prefix attack on MD5 [Ste13]. He uncovered some details that prove that this attack differs fro...

A collision with clearance causes obvious nonlinearity in structures, and dynamic response analysis plays an important role predicting the mechanical performance of structure. The general form nonlinear equation a structure modeling method are introduced, clearance-caused term is expressed by impact forces. Different models local structures presented. relationships between different forces clea...