System and computer program product for allowing a computer to boot from a user trusted device. The computer comprises a long-term data storage device storing operating system (OS) services; and the user trusted device is connectable to the computer and stores: a boot loader, detectable and executable by a firmware of the computer, upon connection of the user trusted device to said computer; an OS loader for the OS; and one or more crypto drivers designed for allowing access to the OS and data, stored encrypted on said data storage device. The user trusted device is designed to prevent unauthenticated access of each of: the boot loader; the one or more crypto drivers; and the OS loader, as stored thereon.