Elisabeth Oswald Manfred Josef Aigner Randomized Addition-Subtraction Chains as a Countermeasure against Power Attacks. 39-50 2001 conf/ches/2001 CHES http://link.springer.de/link/service/series/0558/bibs/2162/21620039.htm db/conf/ches/ches2001.html#OswaldA01