Analysis of the E0 Encryption System

The encryption system E0, which is the encryption system used in the Bluetooth specification, is examined. In the current paper, a method of deriving the cipher key from a set of known keystream bits is given. The running time for this method depends on the amount of known keystream available, varying from O(284 ) if 132 bits are available to O(273 ), given 243 bits of known keystream. Although the attacks are of no advantage if E0 is used with the recommended security parameters (64 bit encryption key), they provide an upper bound on the amount of security that would be made available by enlarging the encryption key, as discussed in the Bluetooth specification.

• Type: Conference
• Year: 2001
• Where: SACRYPT
• Authors: Scott R. Fluhrer, Stefan Lucks
• Keywords: Bluetooth Specification, Cryptology, Encryption, Encryption Key, SACRYPT 2001