Puzzle for March 11, 2002

"Our ancestors, and those who were considered to be wise, were accustomed to say that it was necessary to control Pistoia by means of factions and Pisa by means of fortresses; so they fostered strife in various of their subject towns, so as to control them more easily. In those days, when there was stability of a sort in Italy, this was doubtless sensible; but I do not think it makes a good rule today. I do not believe any good at all ever comes from dissension. On the contrary, on the approach of the enemy, cities which are so divided inevitably succumb at once; the weaker faction will always go over to the invader, and the other will not be able to hold out."1

What does this paragraph say to a system administrator or security officer seeking insight to defend her systems?

1. Niccolò Machiavelli, The Prince, George Bull trans., Penguin Books, New York, NY ©1995, p. 67

ECS 153, Introduction to Computer Security
Winter Quarter 2002
Email: cs153@cs.ucdavis.edu