| Patent application number | Description | Published |
| 20090028327 | SECURE CONTENT KEY DISTRIBUTION USING MULTIPLE DISTINCT METHODS - Systems and methods of secure content key distribution using multiple distinct methods are disclosed herein. Example embodiments include receiving multiple distinct control words from multiple conditional access systems and encrypting packets or a group of packets using the multiple distinct control words. | 01-29-2009 |
| 20090080648 | CONTROLLED CRYPTOPERIOD TIMING TO REDUCE DECODER PROCESSING LOAD - Systems and methods are disclosed for enabling encryptor devices to provide real-time messages having offset cryptoperiods according to an offset algorithm within common crypto-sync pulse boundaries. A master clock aligns the encryptor devices to a common crypto-sync pulse. Subsequently, a cryptoperiod offset aligner assigns a different offset value according to an algorithm to each encrypted service. The corresponding encryptor device then begins the cryptoperiod, during which real-time messages are transmitted, at the assigned offset value from the common crypto-sync pulse. | 03-26-2009 |
| 20090089369 | Apparatus for Entitling and Transmitting Service Instances to Remote Client Devices - A server in a subscriber television network receives service instances from a headend of the subscriber television network. The server is adapted to encrypt according to an encryption scheme and re-transmit service instances to a client-receiver. The server reformats the service instance from a first format into a second format the client-receiver can access the service instance. | 04-02-2009 |
| 20100241872 | Partially Reversible Key Obfuscation - Techniques are provided to obfuscate seed values to produce a decryption key for a simplified content protection scheme. A first repeatable sequence is performed that encrypts a value stored in a first memory location using a value stored in the second memory location to produce an encrypted value and the value stored in the first memory location is overwritten with the encrypted value and then applying a constraining function to the value stored in the second memory location to produce a result and the value stored in the second memory location is overwritten with the result, wherein the result contains a less entropy compared an entropy level of the value in the second memory location prior to applying the constraining function. This sequence is repeated, but the values used in the first and second memory locations are used in opposite fashion. Techniques are also provided to perform the reverse operation and de-obfuscate a decryption key. | 09-23-2010 |
| 20110013773 | USE OF COPYRIGHT TEXT IN KEY DERIVATION FUNCTION - Consistent with embodiments of the present invention, systems and methods are disclosed for deriving a secure key. In some embodiments, a method for deriving a key may be provided comprising: generating a first input value; loading a first register with the first input value; generating a second input value; loading a second register with the second input value; updating the first register and the second register at the same time, where the step of updating comprises: applying a first update function to the current value of the second register to determine a third input value; applying an XOR function to the third input value and a fixed string to determine a fourth input value, wherein the fixed string contains a legal notice; incrementing an offset to the fixed string; storing the fourth input value in the first register; applying a second update function to the current values of the first register and the second register to determine a fifth input value; storing the fifth input value in the second register; repeating the step of updating the first register and the second register a predetermined number of times; and outputting the value of the second register as the key. | 01-20-2011 |
| 20110091037 | CONTENT PROTECTION KEY ENCRYPTOR FOR SECURITY PROVIDERS - Techniques are provided to receive at an encryption device from a control device an encryption request comprising a message and an identifier for a device. The control device and the device are associated with a security provider that provides secure content to the device using the message encrypted with a device key that is securely embedded in the device and also stored on the encryption device. The encryption device is associated with a key provider and the device key is not divulged to the security provider. At the encryption device, the device key is retrieved based on the identifier. The message is encrypted with the device key using a predetermined algorithm, and the encrypted message is then sent to the control device. | 04-21-2011 |