A data storage device that can be reversibly associated with one or more of a plurality of hosts. A “trusted” host on which the device is mounted is allowed access to a secure data area of the device automatically, without the user having to enter a password. Ways in which a host is designated as “trusted” include storing the host's ID in a trusted host list of the device, storing a representation of the host's ID that was encrypted using a trust key of the device in a cookie in the host, or storing a storage password of the device in a password list of the host. Alternatively, an untrusted host is allowed access to the secure data area if a user enters a correct user password.