Wireless Transport Layer Security protocal (WTLS) does all cryptography oriented features of WAP. WTLS handles encryption/decryption, user authentication and data integrity. WTLS is based on the fixed network Transport Layer Security protocal (TLS), formerly known as Secure Sockets Layer (SSL).

CRYPT()
MD5()

The reverse application of an encryption algorithm to encrypted data, thereby restoring that data to its original, unencrypted state.

The Bluetooth specification 1.0 describes the link encryption algorithm as a stream cipher using 4 LFSR (linear feedback shift registers). The sum of the width of the LFSRs is 128, and the spec says "the effective key length is selectable between 8 and 128 bits". This arrangement allows Bluetooth to be used in countries with regulations limiting encryption strength, and "facilitate a future upgrade path for the security without the need for a costly redesign of the algorithms and encryption hardware" according to the Bluetooth specification. Key generation and authentication seems to be using the 8-round SAFER+ encryption algorithm. The information available suggests that Bluetooth security will be adequate for most purposes; but users with higher security requirements will need to employ stronger algorithms to ensure the security of their data.

Pairs of devices may establish a trusted relationship by learning (by user input) a shared secret known as a "passkey". A device that wants to communicate only with a trusted device can cryptographically authenticate the identity of the other device. Trusted devices may also encrypt the data that they exchange over the air so that no one can listen in. The encryption can however be turned off and passkeys are stored on the device's file system and not the Bluetooth chip itself. Since the Bluetooth address is permanent a pairing will be preserved even if the Bluetooth name is changed. Pairs can be deleted at any time by either device. Devices will generally require pairing or will prompt the owner before it allows a remote device to use any or most of its services. Some devices such as Sony Ericsson phones will usually accept OBEX business cards and notes without any pairing or prompts. Certain printers and access points will allow any device to use its services by default much like unsecured Wi-Fi networks.

Use the WITH CHECK OPTION or the WITH ENCRYPTION clause. Define the view using joins to include data from two or more tables.