Steganographic techniques for securely delivering electronic digital rights management control information over insecure communication channels
View Patent ↗Electronic steganographic techniques can be used to encode a rights management control signal onto an information signal carried over an insecure communications channel. Steganographic techniques ensure that the digital control information is substantially invisibly and substantially indelibly carried by the information signal. These techniques can provide end-to-end rights management protection of an information signal irrespective of transformations between analog and digital. An electronic appliance can recover the control information and use it for electronic rights management to provide compatibility with a Virtual Distribution Environment. In one example, the system encodes low data rate pointers within high bandwidth time periods of the content signal to improve overall control information read/seek times.
1. A rights management method comprising the steps of:
(a) receiving an information signal at a first device over a communication channel, the information signal comprising a content portion that has been steganographically encoded with control information, the control information being intertwined with the content portion of the information signal in locations based on the available bandwidth of the communications channel, the control information comprising an indication of a number of times the content portion may be rendered by a given device, as well as an indication of whether at least part of the content portion may be copied to another device, and whether the control information must be refreshed prior to copying to another device;
(b) steganographically decoding the received information signal to recover the control information;
(c) using the control information to determine whether the content portion may be rendered by the first device;
(d) rendering the content portion on the first device if permitted by the control information;
(e) using the control information to determine whether at least part of the information signal may be copied to a second device;
(f) refreshing the control information using a refresh decoder and steganographically encoding the content portion with the refreshed control information, if permitted by the control information; and
(g) copying at least part of the information signal to the second device if permitted by the control information.
2. A method as in claim 1 , in which the control information further comprises an indication that the content may be copied only to appliances that are capable of enforcing the control information.
3. A method as in claim 1 , in which the control information further comprises an expiration date after which the content cannot be used.
4. A method as in claim 1 , in which the control information further comprises an indication that the content may be rendered on an audio or video output.
5. A method as in claim 1 , in which the control information further comprises an indication of the number of times the information signal may be copied.
6. A method as in claim 1 , further comprising using the control information to govern at least one rendering of the content on the first device, including degrading the quality of the content.
7. A method as in claim 1 , further comprising rendering the content on the second device if permitted by the refreshed control information.
8. A method as in claim 7 , further comprising using the refreshed control information to govern at least one rendering of the content on the second device, including degrading the quality of the content.