Patent EA-003963-B1 (EA)
Title: Controlled distributing of digital information, in particular audio
Inventor: KAMPERMAN FRANCISCUS L A J
IPC: G10L19/00
Filed: 2001-04-20
Abstract: 1. Method for controlled distributing of digital information, in particular audio, in which -at least part of the digital information is encrypted using an encryption key and transferred to a rendering device, -a decryption key corresponding to the encryption key is transferred to the rendering device for decrypting the digital information, -the rendering device is provided with a public device identifier and a secret device identifier, which identifier and key are also stored in a remote database, -the digital information is provided with an information identifier, -the public device identifier and the information identifier are transferred to an access center, -the remote database or the access center generates a personalized access code in dependence of the information identifier and the secret device identifier, -the personalized access code is transferred to the rendering device, and -the rendering device verifies the personalized access code using the secret device identifier and the information identifier and, in dependence thereon, makes the information available to the user. 2. Method as claimed in claim1, wherein the public device identifier, the information identifier, and the personalized access code are transferred via a data network. 3. Method as claimed in claim 2, wherein the digital information is provided with an address of the access center on the data network. 4. Method as claimed in claim 1, wherein the public device identifier and/or the personalized access code are non uniquely selected from a limited set of numbers. 5. Method for providing personalized access codes for use in the method of claim 1, in which -a public device identifier identifying a rendering device and an information identifier identifying digital information are received, -a secret device identifier is recovered from a database based on the public device identifier, -the personalized access code is generated in dependence of the information identifier and the secret device identifier, -the personalized access code is transferred to a rendering device. 6. Method as claimed in claim 5, wherein the total number of personalized access codes is limited, or the personalized access codes are only provided within a predetermined period of time. 7. Method as claimed in claim 5, wherein the secret device identifier is recovered from one of a multiple of databases, of which at least one is maintained by a manufacturer of rendering devices. 8. Information carrier for use in the method of claim 1, comprising digital information, in particular audio, in encrypted form, an decryption key for decrypting the digital information, an information identifier identifying digital information, and an access indicator for indicating a requirement for a personalized access code before allowing access to the digital information, the personalized access code being dependent on the information identifier and the rendering device. 9. Information carrier as claimed in claim 8, wherein the access indicator is arranged for indicating said requirement only for selected parts of the digital information. 10. Information carrier as claimed in claim 8 or 9, wherein the information is represented by optically readable marks in a track. 11. Information carrier as claimed in claim 10, wherein the decryption key is represented in a parameter of the track different from the optically readable marks, in particular in a track wobble. 12. Access signal for use in the method of claim 1, comprising a personalized access code for enabling access to digital information, in particular audio, in encrypted form using a decryption key for decrypting the digital information in a rendering device, the personalized access code being dependent on an information identifier identifying digital information and the rendering device. 13. Rendering device for use in the method of claim 1, for rendering digital information, in particular audio, for a user, which device comprises -means for receiving the digital information in encrypted form, a corresponding information identifier and a decryption key, -means for decrypting the digital information using the decryption key, means for decrypting is connected to the means for receiving, -control means for receiving a personalized access code and for verifying the personalized access code using the secret device identifier and the information identifier, the control means is connected to the means for decrypting -a memory connected to the control means and comprising a public device identifier and a secret device identifier, and -switching means for, in dependence on said verifying, enabling access of the user to the information, wherein the switching means is connected to the means for decrypting and to the means for receiving.. 14. Rendering device as claimed in claim 13, wherein the control means comprise a hash function based on a block cipher. 15. Rendering device as claimed in claim 13, the device comprising an access code memory for storing at least one information identifier and the corresponding personalized access code, the verification means being arranged for reading the personalized access code from the access code memory for enabling the access to information of which the information identifier is present in the memory. 16. Access control software product for use in the method as claimed in claim 1, for enabling access to encrypted digital information on a rendering device, the software product having computer executable instructions for -receiving a personalized access code, a secret device identifier and an information identifier, -verifying the personalized access code using the secret device identifier and the information identifier and, in dependence thereon, and -enabling access of the user to the information. 17. Access control software product as claimed in claim 16, wherein the software includes a public device identifier and a secret device identifier. 18. Record carrier comprising the access control software product as claimed in claims 16 or 17.