Abstract: A system and method that enables secure system boot up with a restricted central processing unit (CPU). The system includes a memory, a segmenting device, and a security sub-system. The memory is a NAND flash memory with a block structure that comprises a guaranteed block and non-guaranteed blocks. The guaranteed block is guaranteed to be useable. A boot code is segmented into boot code segments and the boot code segments are stored separately in the guaranteed and non-guaranteed blocks. The security sub-system is configured to locate the boot code segments stored in the non-guaranteed blocks and validate them independently based on data in the guaranteed block. The security sub-system is further configured to assemble the boot code segments into the boot code and execute the boot code.

Abstract: Methods, devices, systems and computer program products are provided to facilitate cryptographically secure retrieval of secret information that is embedded in a device. The embedded secret information can include a random number that is not custom-designed for any specific requestor of the secret information. Upon receiving a request for the embedded secret information, an encrypted secret is provided to the requestor that enables the recovery of the embedded secret information by only the requestor. Moreover, a need for maintenance of a database of the embedded secret information and the associated requestors is eliminated.

Abstract: Securely loading code in a security processor may include autonomous fetching an encrypted security data set, which may comprise security code and/or root keys, by a security processor integrated within a chip. The encrypted security data set may be decrypted via the on-chip security processor and the decrypted code set may be validated on-chip using an on-chip locked value. The on-chip locked value may be stored in a one-time programmable read-only memory (OTP ROM) and may include security information generated by applying one or more security algorithms, for example SHA-based algorithms, to the security data set. The encryption of the security data set may utilize various security algorithms, for example AES-based algorithms. The on-chip locked value may be created and locked after a virgin boot of a device that includes the security processor. The security data set may be authenticated during the virgin boot of the device.

Abstract: A computing system, comprising includes a first central processing unit (CPU) and a second CPU coupled with the first CPU and with a host processor. The second CPU and the host processor may both request the first CPU to generate keys that have access rights to regions of memory to access specific data. The first CPU may be configured to, in response to a request from the second CPU, generate a unique key with a unique access right to a region of memory, the unique key usable only by the second CPU, not the host processor.

Abstract: A computing system includes a first security central processing unit (SCPU) of a system-on-a-chip (SOC), the first SCPU configured to execute functions of a first security level. The computing system also includes a second SCPU of the SOC coupled with the first SCPU and coupled with a host processor, the second SCPU configured to execute functions of a second security level less secure than the first security level, and the second SCPU executing functions not executed by the first SCPU.

Abstract: A method for managing a transcoder pipeline includes partitioning a memory with a numbered region; receiving an incoming media stream to be transcoded; and atomically loading, using a security central processing unit (SCPU), a decryption key, a counterpart encryption key and an associated region number of the memory into a slot of a key table, the key table providing selection of decryption and encryption keys during transcoding. The atomically loading the decryption and encryption keys and the associated numbered region ensures that the encryption key is selected to encrypt a transcoded version of the media stream when the media stream has been decrypted with the decryption key and the transcoded media stream is retrieved from the associated numbered region of the memory.

Abstract: 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.

Abstract: A set-top-box has on-chip OTP memory emulated using an external flash memory and a series of on-chip fuses. The external memory is comprised of one or more regions, each having its own unique region identification. Each on-chip fuse corresponds to one of the memory regions and comprises a component which can be caused to change to a particular (blown) state irreversibly. When data first needs to be written to a region of the external memory, the identification of that region is appended to the data itself together with a parity field and a validity field. The resultant data packet is then encrypted by a cryptographic circuit using a secret key unique to the set-top-box and the encrypted data packet is written to the specified region of the external memory. Then, the on-chip fuse corresponding to the region that has been written to is irreversibly blown, effectively locking that region.

Abstract: Methods, devices, systems and computer program products are provided to facilitate cryptographically secure retrieval of secret information that is embedded in a device. The embedded secret information can include a random number that is not custom-designed for any specific requestor of the secret information. Upon receiving a request for the embedded secret information, an encrypted secret is provided to the requestor that enables the recovery of the embedded secret information by only the requestor. Moreover, a need for maintenance of a database of the embedded secret information and the associated requestors is eliminated.

Abstract: A portion of data is obfuscated by performing a bitwise XOR function between bits of the data portion and bits of a mask. The mask is generated based on the memory address of the data portion. A bitfield representing the memory address of the data portion is split into subset bitfields. Each subset then forms the input of a corresponding primary randomizing unit. Each primary randomizing unit is arranged to generate an output bitfield that appears to be randomly correlated with the input, but which may be determined from the input if certain secret information is known. The output of the primary randomizing units is input into a series of secondary randomizing units. Each secondary randomizing unit is arranged to input at least one bit of the output of every primary randomizing unit. The output of the secondary randomizing units are then combined by concatenation to form a data mask.

Abstract: A stored predefined unmodifiable bootable code set may be verified during code reprogramming of a device, and executed as a first stage of code reprogramming of the device. The predefined unmodifiable bootable code set may be stored in a locked memory such as a locked flash memory and may comprise code that enables minimal communication functionality of the device. The predefined unmodifiable bootable code set may be verified using a security algorithm, for example, a SHA-based algorithm. Information necessary for the security algorithm may be stored in a memory, for example, a one-time programmable read-only memory (OTP ROM). The stored information necessary for the security algorithm may comprise a SHA digest, a signature, and/or a key. A second stage code set may be verified and executed during the code reprogramming of the device subsequent to the verification of the stored predefined unmodifiable bootable code set.

Abstract: Methods and systems for protecting data may include controlling encryption and/or decryption, utilizing an encryption/decryption algorithm, rights related to the source and destination addresses, and encryption/decryption keys. 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 rights 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 received from an external source or generated within the chip. The encryption/decryption algorithm may be selected based on two or more encryption/decryption algorithms, and additionally based on the source address, destination address, source rights, and destination rights.

Abstract: Methods and systems for protection of customer secrets in a secure reprogrammable system are disclosed, and may include controlling, via hardware logic and firmware, access to customer specific functions. The firmware may comprise trusted code, and may comprise boot code, stored in non-volatile memory, which may comprise read only memory, or a locked flash memory. A customer mode may be checked via the trusted code prior to allowing downloading of code written by a customer to the reprogrammable system. Access to customer specific functions may be restricted via commands from a trusted source. The hardware logic may be latched at startup in a disabled mode by the firmware, determined by the customer mode stored in a one time programmable memory. The customer mode may be re-checked utilizing the firmware, and may disallow the use of code other than trusted code in the reprogrammable system when the re-checking fails.

Abstract: Methods and systems for software security in a secure communication system are disclosed and may include verifying downloaded code in a reprogrammable system and reloading prestored unmodifiable first stage code upon failure. The prestored unmodifiable first stage code, which may comprise boot code for the reprogrammable system, may be stored in locked flash, and the downloaded software code may be stored in unlocked flash. The downloaded software code may be verified by comparing a signature of the downloaded code to a private key. A first sticky bit may be utilized to indicate a failure of the verification and a second sticky bit may be utilized to indicate passing of the verification and the use of the downloaded software code. Whether to reset the reprogrammable system and reload the prestored unmodifiable first stage code may be determined from within the reprogrammable system, which may comprise a set-top box.

Abstract: A boot code may be segmented to allow separate and independent storage of the code segments in a manner that may enable secure system boot by autonomous fetching and assembling of the boot code by a security sub-system. The code fetching may need to be done without the main CPU running on the chip for security reasons. Because the boot code may be stored in memory devices that require special software application to account for non-contiguous storage of data and/or code, for example a NAND flash memory which would require such an application as Bad Block Management, code segments stored in areas guaranteed to be usable may enable loading remaining segment separately and independently. Each of the code segments may be validated, wherein validation of the code segments may comprise use of hardware-based signatures.

Abstract: A method distributes personalized circuits to one or more parties. The method distributes a generic circuit to each party, encrypts a unique personalization value using a secret encryption key, and transmits each encrypted personalization value to the corresponding party. Each party then stores the encrypted personalization value in their circuit. The stored encrypted personalization value allows a piece of software to be properly executed by the circuit. A semiconductor integrated circuit is arranged to execute a piece of software that inputs a personalization value as an input parameter. The circuit comprises a personalization memory arranged to store an encrypted personalization value; a key memory for storing a decryption key; a control unit comprising a cryptographic circuit arranged to decrypt the encrypted personalization value using the decryption key; and a processor arranged to receive the decrypted personalization value and execute the software using the decrypted personalization value.

Abstract: Methods, devices, systems and computer program products are provided to facilitate cryptographically secure retrieval of secret information that is embedded in a device. The embedded secret information can include a random number that is not custom-designed for any specific requestor of the secret information. Upon receiving a request for the embedded secret information, an encrypted secret is provided to the requestor that enables the recovery of the embedded secret information by only the requestor. Moreover, a need for maintenance of a database of the embedded secret information and the associated requestors is eliminated.

Abstract: A semiconductor integrated circuit for the processing of conditional access television signals that includes an input interface for receiving encrypted television signals and an output interface for output of decrypted television signals. The semiconductor integrated circuit is provided with some functionality restricted in some way by preventing one or more hardware circuit elements from operating, such as an MPEG decoder, display engine, IO ports or main CPU. To enable the functionality, a subscriber must pay for a service and then receives an encrypted message broadcast to the semiconductor integrated circuit that is decrypted and instructs functionality to be turned on or off.

Abstract: 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.

Abstract: 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.