When the USB key is used by connecting the key to a computer, the driver may be configured to start running and query the user in order to determine whether or not the user is associated with the first user profile. If the user is not associated with the first user profile, he or she may be associated by default with the second user profile. The user can thus place data files in the “drop zone” in order to share them with a user of the first user profile, without being able to see the data already stored in the “drop zone”, with the exception of the files that this user has stored in the “drop zone”. He or she may also find out the available storage capacity in the “drop zone”, for example by means of a graphical interface displayed on the screen of his or her computer, this capacity being updated as files are placed in the “drop zone”. The user may also be informed that his or her data will be stored for a predetermined time in the “drop zone” (for example 1 hour) before they are erased by the driver for the key.

A first-profile user can access the data deposited in the “drop zone” by another user, after successful identification and possibly authentication. He or she can thus read, modify, move, and delete the files deposited in the “drop zone”, and can access the access log to find out about write accesses by other users.