| Patent application number | Description | Published |
|---|
| 20080222428 | Method for Securing Authenticity of Data in a Digital Processing System - The invention describes a method and a corresponding digital processing system for ensuring that data is unmodified while reducing the amount of one-time programmable memory in the system. The data is stored in modifiable memory and an authentication value of the data is stored in unmodifiable memory. Before the data is used according to its purpose the digital processing system authenticates that the data is unmodified, for example by using a cryptographic hash algorithm. | 09-11-2008 |
| 20080267410 | Method for Authorizing and Authenticating Data - A method and a corresponding apparatus for authenticating data in a digital processing system (DPS) is disclosed, wherein a root/first tier key pair associated with a first tier/root authority may sign data and second tier keys for authorizing data for processing in the DPS. The first tier/root authority may pass entitlements to the authorized second tier key, which may itself authorize third tier keys and pass entitlements to said key. | 10-30-2008 |
| 20080271164 | METHOD AND SYSTEM FOR ALLOWING NO CODE DOWNLOAD IN A CODE DOWNLOAD SCHEME - Aspects of a method and system for allowing no code download in a code download scheme are provided. A system-on-a-chip (SoC) may comprise a security processor, a ROM, and a one-time-programmable (OTP) memory. The security processor may enable fetching code from a restricted function portion of the ROM. The restricted functions may comprise code for booting up the SoC and code that prevents enabling security algorithms within the SoC. The security processor may then enable booting up of at least a portion of the SoC based on the fetched code. The remaining portion of the ROM may comprise code for downloading security code from an external memory, such as a FLASH memory, to an internal memory, such as a RAM, to boot up the SoC. Access to the restricted function portion or the remaining portion of the ROM is based on at least one bit from the OTP memory. | 10-30-2008 |
| 20090080649 | METHOD AND SYSTEM FOR PROTECTING DATA - Methods and systems for protecting data may include controlling encryption and/or decryption and identifying a destination of corresponding encrypted and/or decrypted data, utilizing rules based on a source location of the data prior to the encryption or decryption and an algorithm that may have been previously utilized for encrypting and/or decrypting the data prior to the data being stored in the source location. The source location and/or destination of the data may comprise protected or unprotected memory. One or more of a plurality of algorithms may be utilized for the encryption and/or decryption. The rules may be stored in a key table, which may be stored on-chip, and may be reprogrammable. One or more keys for the encryption and/or decryption may be generated within the chip. | 03-26-2009 |
| 20090190762 | METHOD AND SYSTEM FOR PREVENTING GENERATION OF DECRYPTION KEYS VIA SAMPLE GATHERING - Methods and systems for preventing generation of decryption keys via statistical sample gathering may include verifying a one-key message authentication code (OMAC) decryption key in received data and inserting a delay time before subsequent OMAC verifications upon a failure of the verifying. The delay time may be increased, doubled, for example, with each failure of the subsequent OMAC verifications. The cryptographic system may be disabled upon reaching a defined number of OMAC verification failures. The delay time may be reset upon an OMAC verification pass. A number of OMAC verification failures may be stored in non-volatile memory. The OMAC verification may be one of a plurality of key verifications in a key ladder system. A service provider may be required to reset the cryptographic system when the cryptographic system may be disabled due to multiple OMAC failures. The received data may be AES, DES or 3-DES encrypted. | 07-30-2009 |
| 20100254536 | Authenticated mode control - Methods and systems for authenticated mode control in controlled devices are disclosed. A method for changing a mode in a controlled device from a current mode includes selecting one of several available key derivation functions based on a target mode, generating a target mode specific root key using a global root key and the selected key derivation function, and the use of that root key to affect a change of the controlled device to a target mode. Corresponding devices and systems are also disclosed. In one embodiment, the methods are applicable to a cable television distribution system and the changing of the operating mode of a set top box from one conditional access provider to another. | 10-07-2010 |
