Apparatus, methods, and systems for pre-authentication, keep-authentication, and regain-authentication
AssigneeAnalog Devices, Inc.
InventorsSergey V. Yarygin, Gyudong Kim, Chandlee Harrell
Life of this patent
Estimating the term…
Abstract
Authentication is a key element for content protection. This invention makes the authentication fast and reliable by hiding the authentication, keeping the authentication, and regaining the lost authentication. The embodiments in this invention reduce the complexity and power consumption of the operation significantly.
Claims20
A method for maintaining authentication or reestablishing authentication on an encrypted stream, the method comprising:
- identifying if an inputCtr signal is correct in a High-bandwidth Digital Content Protection (HDCP) environment, with the inputCtr signal defining a 64-bit counter indicative of a number of encrypted frames since start of HDCP encryption;
- checking a section of the encrypted stream;
- performing a packet integrity check on a data island packet;
- performing a packet content check on the data island packet;
- searching for a correct inputCtr;
- and
- resynchronizing to the encrypted stream by applying the correct inputCtr without forcing an HDCP reauthentication when HDCP authentication failure is detected.
A method for maintaining authentication or reestablishing authentication on an encrypted stream, the method comprising:
- identifying if a Ki signal is correct in a High-bandwidth Digital Content Protection (HDCP) environment, with index i representing a frame number of a video frame and the Ki signal defining a 56-bit key to initialize a HDCP cipher;
- checking a section of the encrypted stream;
- performing a packet integrity check on a data island packet;
- performing a packet content check on the data island packet;
- searching for a correct Ki signal;
- and
- resynchronizing to the encrypted stream by applying the correct Ki signal without forcing an HDCP reauthentication when HDCP failure is detected.
An apparatus to maintain authentication or reestablish authentication on an encrypted stream, the apparatus comprising:
- processing circuitry configured at least to:
- identify if an inputCtr signal is correct in a High-bandwidth Digital Content Protection (HDCP) environment, with the inputCtr signal defining a 64-bit counter indicative of a number of encrypted frames since start of HDCP encryption;
- check a section of the encrypted stream;
- perform a packet integrity check on a data island packet;
- perform a packet content check on the data island packet;
- search for a correct InputCtr;
- and
- resynchronize to the encrypted stream by applying the correct inputCtr without forcing an HDCP reauthentication when HDCP failure is detected.
Dependencies are inferred from the claim text.