Dynamic protection structures

Butler Lampson


Citation: Proc. AFIPS Conf. 35 (1969), pp 27-38.

Links: Abstract, Acrobat. Here is an HTML version created by OCR for the benefit of search engines; it is not meant for human consumption.

Email: blampson@microsoft.com. This paper is at http://www.research.microsoft.com.



Protection mechanisms come in many different forms, ranging from hardware which prevents the execution of input/output instructions by user programs, to password schemes for identifying customers when they log on to a time-sharing system. This paper deals one aspect of the subject, which might be called the meta-theory of protection systems: how can the information which specifies protection and authorizes access, itself be protected and manipulated.  Thus, for example, a memory protection system decides whether a program is allowed to store into a memory location.  We are concerned with how the program obtains this permission and passes it on to other programs.