Data encryption in transport
If you use the BlackBerry® Enterprise Server as the network gateway for your application, the BlackBerry Enterprise Server encrypts data using AES or TripleDES encryption at all points in the connection between the BlackBerry device and the BlackBerry Enterprise Server behind the organization's firewall. If you require data to be encrypted further between the BlackBerry Enterprise Server and the destination server, you can use the HTTPS protocol and use SSL/TLS encryption.
If your application uses the BlackBerry® Internet Service or the Internet gateway of the wireless service provider, data traffic is not encrypted. If your BlackBerry device users prefer, you can use HTTPS to encrypt the data, or you can use the Java® APIs for encryption to apply your own symmetric key or public key cryptography.