BlackBerry Internet Service
Source: Research In Motion
The BlackBerry Internet Service uses the security of the wireless network that it connects to. Email messages that are sent between the BlackBerry Internet Service and BlackBerry device are not encrypted. However, email messages that are sent between the BlackBerry Internet Service and messaging server can be encrypted using SSL encryption. SSL encryption can also be used by the BlackBerry Browser and other applications on BlackBerry device to help protect data when one connect to the Internet (for example, while shopping and banking online).