System for securely storing and reading encrypted data on a data medium using a transponder

An apparatus for decrypting data stored on a data medium comprising:

• a reader means, for reading encrypted data from said medium, as well as information for determining a decryption key for said data contained on said data medium, said reader means including decryption means for decrypting said encrypted data with said decryption key;
• a transceiver means, associated with said reader means, for transmitting said information for determining a decryption key and for receiving a decryption key for decrypting said encrypted data;
• and
• a transponder means, associated with said data medium, for receiving said information for determining a decryption key, and generating a decryption key from said information, said transponder means forwarding said decryption key to said transceiver means whereby said reader is provided with a decryption key for decrypting said encrypted data.

A method for providing a secure data medium comprising:

• creating frames of data to be stored on said data medium;
• for each of said frames of data, providing a header containing a frame identifying number;
• encrypting each of said frames of data with an encryption key which is derived from the identifying number of its frame;
• and
• storing said encrypted data frames with said headers on a data medium;
• fixing a transponder means to said data medium, said transponder means including means for determining a decryption key from each frame identifying number.