The article analyzes the main security functions implemented in the JDK in the context of access control mechanisms. Due to more frequent updates introduced in the Java platform, the problem of ensuring backward compatibility arises. The research carried out using the SecurityManager and AccessControl classes shows that the solution to this problem can be achieved through the synergy of the SecurityManager class acting as a central access control point and the AccessControl class ensuring the implementation of an access control algorithm with unique functions. This solution also enables application flexibility when implementing a multi-level security model.