A method and system for renewing software at the component-level is provided. A client program includes a base component for loading a software component into at least one loadable region of the program to update the program. Code in the software component is for writing state data associating the state of the update in storage, upon execution of the software component, and testing the state data to verify condition of the updated program and disallowing rollback and roll-forward attacks, the state data comprising hash chain values. The state data for verifying the correctness of the updated program is entangled with application data used for the program functionality. A server includes: an update pool having a plurality of software updates deployed in each client, and a policy control for monitoring and controlling at least one of: the length of time the client runs until the software update is invoked, a chain of the updates; and the granularity of the update.