Abstract: A circuit for secure operation includes a plurality of mutually exclusive circuit zones including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security and one or more gate circuits each providing limited transfer of data between the circuit zones, the gate circuits providing all data connectivity between the first circuit zone and the second circuit zone and statically configured to prevent unmodified transfer of data from the first circuit zone to the second circuit zone.

Abstract: A method for processing addressable encrypted data representing addressable cleartext data uses an integrated circuit including a processor circuit. The method includes processing the addressable cleartext data in the processor circuit without storing said cleartext data outside the processor circuit.

Abstract: A method for operating a secure device having a plurality of mutually exclusive circuit zones, including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method including unpacking a key exchange package including receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data and processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone.

Abstract: A method for limiting execution of an encrypted computer program on a secure processor includes executing a first set of instructions encoding a test for determining whether a value of a register of the secure processor belongs to a set of valid register values encoded in the encrypted computer program. Execution of the first set of instructions causes the secure processor to read a first register value from the register of the secure processor, the register of the secure processor preventing repeated reads of a same value of the register, and determine whether the first register value belongs to the set of valid register values encoded in the encrypted computer program. Execution of further instructions of the encrypted computer program is prevented if the first register value does not belong to the set of valid register values encoded in the encrypted computer program.

Abstract: A method for operating a secure device having a plurality of mutually exclusive circuit zones, including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method including unpacking a key exchange package including receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data and processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone.

Abstract: A method for operating a secure device having a plurality of mutually exclusive circuit zones, including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method including unpacking a key exchange package including receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data and processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone.

Abstract: A method for operating a secure device having a plurality of mutually exclusive circuit zones, including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method including unpacking a key exchange package including receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data and processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone.

Abstract: A circuit for secure operation includes a plurality of mutually exclusive circuit zones including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security and one or more gate circuits each providing limited transfer of data between the circuit zones, the gate circuits providing all data connectivity between the first circuit zone and the second circuit zone and statically configured to prevent unmodified transfer of data from the first circuit zone to the second circuit zone.

Abstract: A method for operating a secure device having a plurality of mutually exclusive circuit zones, including a first circuit zone having a first level of security and a second circuit zone having a second level of security less than the first level of security, the method including unpacking a key exchange package including receiving a key exchange package in the second circuit zone, the key exchange package including encrypted key data and processing the encrypted key data using a content key in the first circuit zone to generate decrypted key data and storing the decrypted key data in the first circuit zone without disclosing the decrypted key data into the second circuit zone.

Abstract: A system and method for minimizing door related injuries are disclosed. Briefly, a mechanism requiring little or no external power is used to vary the force needed to open a door. If an obstruction (i.e. a person, pet, etc) is within the sweep of the opening door, the force needed by the user to push open the door will be increased, to give the user tactile feedback that an accident may be imminent. The feedback mechanism can be implemented in a variety of ways, including embodiments that require no external power or battery. A sensor is used to detect the presence of an obstruction within the sweep of the door. In a further embodiment, a mechanism is used to slow or stop a door from closing if an obstruction (such as a finger) is in the return path of the door.