John O. Pliam On the Incomparability of Entropy and Marginal Guesswork in Brute-Force Attacks. 67-79 http://link.springer.de/link/service/series/0558/bibs/1977/19770067.htm 2000 conf/indocrypt/2000 INDOCRYPT db/conf/indocrypt/indocrypt2000.html#Pliam00