Shiho Moriai Serge Vaudenay On the Pseudorandomness of Top-Level Schemes of Block Ciphers. 289-302 2000 conf/asiacrypt/2000 ASIACRYPT http://link.springer.de/link/service/series/0558/bibs/1976/19760289.htm db/conf/asiacrypt/asiacrypt2000.html#MoriaiV00