COMPUTER SYSTEM, PROCESSING METHOD AND PROGRAM

PROBLEM TO BE SOLVED: To improve the integrity of policy files, to reduce a communication load for majority processing and to identify tamper time, in a system using the majority processing. SOLUTION: In a computer system including a main node, a plurality of subnodes and a network for connecting therebetween, each node includes a policy file for controlling accesses to resources, and a majority processing part for performing majority processing for controlling the accesses by referring to the policy files; the policy file includes one or more pieces of policy data; the policy data includes data indicating access control common to each node and time stamp data; and the node determines whether a time stamp is a normal value or not before executing the majority processing, sets the state of the policy file of which the time stamp is a normal value to a normal state, and executes the majority processing by using only the policy files that are in the normal state. COPYRIGHT: (C)2010,JPO&INPIT