Information source agent systems and methods for distributed content storage and management using content signatures that use file identicality properties are provided. A data management system is provided that includes a content engine for managing the storage of file content, a content signature generator that generates a unique content signature for a file processed by the content engine, a content signature comparator that compares content signatures and a content signature repository that stores content signatures. Information source agents are provided that include content signature generators and content signature comparators. Methods are provided for the efficient management of files using content signatures that take advantage of file identicality properties. Content signature application modules and registries exist within information source clients and centralized servers to support the content signature methods.