Kurt claims he was working on a last-minute project deadline at the time the files were downloaded. However, several months ago, Kurt's company deployed a security tool that prevents concurrent logins to the network. This means only one person at a time could log in using Kurt's credentials. If he was logged in to work on the project, no one else could use his password even if they knew it. What method is Kurt's company using to establish that Kurt is the responsible party for the downloaded material