Abstract: A method for administering secure access to files of a computer system. For a process-file pair, a first security label associated with the process is compared with a second security label associated with the file in response to a request to read or write the file. If the security label of the destination (file or process) of the read or write operation does not dominate the security label of the source (file or process), the security label of the destination is dynamically raised accordingly. If the security label of the file or process is raised, an indicator associated with this process and with this file is set to a first state representing that the file is safe for this process-file pair. Indicators associated with every other process linked with this file are set to a second state representing that the file is unsafe for those process-file pairs.