Praveen Gauravaram Lars R. Knudsen On Randomizing Hash Functions to Strengthen the Security of Digital Signatures. 88-105 2009 EUROCRYPT http://dx.doi.org/10.1007/978-3-642-01001-9_5 conf/eurocrypt/2009 db/conf/eurocrypt/eurocrypt2009.html#GauravaramK09