唯一真正安全的電腦系統，就是關上電源，丟進水泥塊裡，封進以鉛作襯裡的房間，外面有武裝守衛把守 —— 即使如此我還是會抱持懷疑。
—尤金．史帕福德（美國普渡大學電腦科學系教授、著名電腦安全專家）
“The only truly secure system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards – and even then I have my doubts.”
—Eugene H. Spafford, professor of Computer Sciences at Purdue University and computer security expert
