Protection in Programming Languages Linguistic mechanisms which can be used to protect one subprogram from another's malfunctioning are described. Function-producing functions and various type-tagging schemes are considered. An attempt is made to distinguish between access limitation and authentication. CACM January, 1973 Morris, J. H. Jr. protection, types, environments,trademarks, seals, access keys, access control authentication, secrecy 4.2 4.3 CA730103JB January 24, 1978 4:45 PM 1458 4 2558 1523 4 2558 1603 4 2558 1698 4 2558 1747 4 2558 1748 4 2558 1854 4 2558 1877 4 2558 1960 4 2558 2155 4 2558 2294 4 2558 2377 4 2558 2378 4 2558 2497 4 2558 2558 4 2558 2558 4 2558 2625 4 2558 2632 4 2558 2840 4 2558 2842 4 2558 2941 4 2558 3077 4 2558 3105 4 2558 3144 4 2558 3150 4 2558 1471 5 2558 2060 5 2558 2558 5 2558 2558 5 2558 2558 5 2558 2868 5 2558 2939 5 2558 2941 5 2558 1471 6 2558 2080 6 2558 2204 6 2558 2356 6 2558 2377 6 2558 2380 6 2558 2558 6 2558 2558 6 2558 2558 6 2558 2625 6 2558 2632 6 2558 2651 6 2558