Method for Recording Data Having a Distinctive Feature

Method of extracting fingerprint data from data (10) recorded on a record carrier along a recording track (15) in the form of a recorded pattern (22) wherein

• the fingerprint data (17) are determined upon variations in the channel bit length of the recorded pattern (22), the variations in the channel bit length being a distinctive feature of the recorded pattern.

Apparatus for recording data (10) on a record carrier along a recording track (15), comprising:

• recording means for recording the data, thereby forming a recorded pattern (22) having a channel bit length, and
• synchronization means (89) for controlling the channel bit length, further comprising perturbation means are present for imposing an uncontrollable perturbation to the synchronization means, so as to cause the recorded pattern to have variations in the channel bit length.

Apparatus for extracting fingerprint data from data (10) recorded on a record carrier along a recording track (15) in the form of a recorded pattern (22),

• configured for determining the fingerprint data (17) upon variations in the channel bit length of the recorded pattern (22), the variations in the channel bit length being a distinctive feature of the recorded pattern.

Record carrier having recorded data (10) along a recording track (15), in the form of a recorded pattern (22) having variations in a channel bit length, the variations in the channel bit length being a distinctive feature of the recorded pattern.