Abstract: A messaging application configured to provide a messaging interface on which outgoing messages from a user, to contacts can be composed and incoming messages from the contacts can be viewed. Moreover, the messaging application is configured to store message data in an encrypted form as a database file. Furthermore, the messaging application is configured to require the user to input a predetermined access code before giving access to the messaging interface. Moreover, the messaging application is configured to provide a first mode in which the user is given access to all message data when a first predetermined access code is input, and a second, secret mode in which the user is given access to only a subset of all the message data, when a second predetermined access code is input by the user.

Abstract: A mobile communication device comprising a microphone; a display; a computer storage configured to store an operating system, a messaging application, and one or more other software applications; and a processor configured to execute the messaging application. The messaging application is configured to check for conditions including a status of the operating system and for presence of test-keys; presence of software applications that allow access to the mobile communication device in root mode thereof; and/or an ability to perform operations on behalf of a root user; wherein if the mobile communication device is considered compromised, a visual warning message is displayed on the display.

Abstract: A messaging application for a messaging service for an electronic communications device including a data store, the application being configured to: store, in encrypted form, message data for an identity registered on the messaging service as a database file on the electronic communications device; require a user to input a predetermined access code for the registered identity before giving the user access to the stored message data; and delete from the device the database file containing the encrypted message data in the event that a particular different predetermined code other than the predetermined access code is provided in place of the predetermined access code.

Abstract: A user device stores a messaging application and an encrypted database, processor and has a key store storing an authorisation token to be used by the messaging application. The messaging application is configured, in the unlaunched state, to retrieve the authorisation token from the key store to perform communication with the messaging server on receipt of an incoming call from the messaging server and to display a notification without contact information, and is configured, in the launched state, on receipt of an incoming call from the messaging server to retrieve the authorisation token from volatile memory to perform communication with the messaging server, and to display a notification of the incoming call with contact information for a calling party, on the display of the user device. The encryption key for the database is generated based on a user passcode, and the user device stores neither the user's passcode nor a hash of the passcode.