Dan Kaminsky Meredith L. Patterson Len Sassaman PKI Layer Cake: New Collision Attacks against the Global X.509 Infrastructure. 289-303 2010 Financial Cryptography http://dx.doi.org/10.1007/978-3-642-14577-3_22 conf/fc/2010 db/conf/fc/fc2010.html#KaminskyPS10