Kaspersky Lab has been granted a wide-ranging patent that might be of interest to anyone who has ever complained about the time it takes for anti-virus programs to scan PC files.
US patent number 7392544 gives the Russian company the intellectual rights to a technique for varying scanning speeds dynamically according to a number of parameters such as file size, format, structure, whether it has been signed, and where the file might have come from.
The overwhelming majority of files on a PC will be wholly innocent, and yet today signature-scanning anti-virus programs still treat all files in broadly the same way unless specifically told to ignore them by altering the default settings. Scans can be quick and relatively insecure or thorough but much slower, a disquieting Hobson's choice for most users.
"One of the problems in the field of anti-virus software is the fact that many users are unwilling to wait for a long time for the anti-virus software to do its work," notes the patent application document.
The innovative element - and why the patent might be worth something - is that it includes the ability to vary scanning time based on file origins. This would include whether the file was received for the web, email or via an instant messaging program, facts that immediately raise the chances of the files being suspect.
Focussing on suspect files based on such parameters has the potential to drop scan times and free users from having to exclude files based on possibly uninformed choices. Although not a new concept as such, the key is being able to do it anew or dynamically each time a scan is started.
It's not clear whether any rival vendors would be affected by the Kaspersky patent - software makers usually keep the subtleties of scanning techniques under wraps. The company says its patents are widely used by rivals already.
The company has also been granted a US patent on a rootkit detection technique that involves taking snapshots of the OS and registry files before and after loading non-boot drivers.