SPECKLE PATTERN FOR AUTHENTICATING AN INFORMATION CARRIER

摘要

The invention relates to a system comprising an information carrier (11) having an optical identifier (12), and an apparatus (10), wherein the apparatus prior to accessing the information carrier verifies if the optical behavior of the optical identifier is consistent with authentication information (17) present in the information carrier. The authentication is performed by challenging the optical identifier with a least one light beam (14), detecting a resulting speckle pattern (16) on a detector (15) as a corresponding response, and comparing it with the authentication information (17). Access to the information carrier can be made conditional to a successful authentication, in particular by encrypting user-information (20) present in the information carrier, and thereby providing a strong copy protection scheme. The invention can be applied for example to optical disks or smart cards. The invention further relates to the information carrier, the apparatus, a method for the authentication and a computer program.