SETT FOR SKYDD MOT TILLBAKAOVERFORING AV PA EN DATABERARE EN GANG REGISTRERAD INFORMATION SAMT ANORDNING FOR IN- OCH/ELLER UTLESNING AV MOT TILLBAKAOVERFORING SKYDDAD INFORMATION

摘要

A method of safeguarding against the re-transfer of uniquely recorded information on a data carrier (1) which includes the recording of the information data and in addition thereto simultaneously recording of additional information on the data carrier (1) which reflects co-ordination characteristics relative to the data carrier. In order to carry out the method an apparatus is provided for recording and/or reading a re-transfer protected information on a data carrier (1) with recording and/or reading device (4). The apparatus comprises a device (13) for detecting measurable properties (3) which are present at singular points of the data carrier (1) and for producing additional information characterizing such properties.