A handheld electronic device comprising: a memory device and a processor. The memory device is temporarily removable from the handheld electronic device for connection with another device. The removable memory device includes a data base structure in which a secret is associated with a predetermined identifier, such that querying the database structure using the predetermined identifier returns the secret. The removable memory device also includes an interface that enables the handheld electronic device to amend and query the data base structure and enables the another device to query the database structure using the predetermined identifier to obtain the secret. The processor is for amending the database structure and for querying the data base structure, wherein querying the database structure using the predetermined identifier returns the secret.
