A Note on the Confinement Problem This note explores the problem of confining a program during its execution so that it cannot transmit information to any other program except its caller. A set of examples attempts to stake out the boundaries of the problem. Necessary conditions for a solution are stated and informally justified. CACM October, 1973 Lampson, B. W. protection, confinement, proprietary program, privacy, security, leakage of data 2.11 4.30 CA731004 JB January 20, 1978 11:41 AM 2436 4 2436 2626 4 2436 2868 4 2436 2870 4 2436 2377 5 2436 2436 5 2436 2436 5 2436 2436 5 2436 2840 5 2436 2869 5 2436 3128 5 2436 3158 5 2436 1471 6 2436 1746 6 2436 2150 6 2436 2356 6 2436 2376 6 2436 2436 6 2436 2436 6 2436 2436 6 2436 2436 6 2436 2597 6 2436 2626 6 2436 2629 6 2436 2865 6 2436 2866 6 2436 2870 6 2436 2912 6 2436 3038 6 2436 3082 6 2436 3111 6 2436