Improved system and approaches for centralized storage of access restrictions which are associated with public keys are disclosed. The access restrictions serve to limit access to files secured by a security system. According to one aspect of the present invention, identifiers, or encoded versions thereof, are used as public keys to identify particular access restrictions. The identifiers to the access restrictions are used in a decentralized manner for public keys, while the access restrictions themselves are maintained in a centralized manner. As compared to the access restrictions, the public keys based on identifiers tend to be smaller and more uniform in size. The centralized storage of the access restrictions also facilitates subsequent changes to access restrictions for previously secured files. The improved system and approaches is particularly suitable in an enterprise environment.