Abstract: A method for generating ultrashort pulses includes directing a master beam having ultrashort pulses and at least one slave beam through an optical gate material. The intensity of the slave beam upstream of the optical gate material is lower than that of the master beam upstream of the optical gate material. The optical gate material and the pulses of the master beam are chosen to induce a Kerr effect when the master beam passes through the optical gate material, the Kerr effect producing a modulation of the phase of the slave beam in association with pulses of the master beam when the slave beam passes through the optical gate material. The modulation of the phase of the slave beam is transformed into a modulation of the amplitude thereof using a complementary optical device to generate a slave beam downstream of the optical gate material having ultrashort pulses.

Abstract: A computer system, especially but not exclusively an embedded system, is provided with a CPU and an external FLASH or other memory which is used for storing code to be executed by the CPU in operation of the system. The system can be initialized without requiring a secondary boot sequence which means it can be used in preference to embedded or serial FLASH solutions. There is provided a computer system comprising: a processor; an external memory, being external to the processor; a memory controller for the external memory; and a power management unit which is arranged to receive a wake up signal, then to first wake up the memory controller; and secondly at a later time to wake up the processor.

Abstract: Methods and apparatus are provided for authenticated pattern matching and authenticated exact path queries on outsourced data by a third party server. A source of the outsourced data computes verification information for node and suffix accumulators and sends the data, accumulation values and suffix tree or label trie information to the server; and publishes its public key and the verification digests. The verification may comprise an accumulation tree (AT) or any other public key authentication scheme, such as digital signatures, Merkle Trees and publishing the accumulation values. The server receives the query from a client and the server computes an answer ? to the query and a verification proof that are provided to the client. The client then verifies the answer.

Abstract: A computer system, especially but not exclusively an embedded system, is provided with a CPU and an external FLASH or other memory which is used for storing code to be executed by the CPU in operation of the system. The system can be initialized without requiring a secondary boot sequence which means it can be used in preference to embedded or serial FLASH solutions. There is provided a computer system comprising: a processor; an external memory, being external to the processor; a memory controller for the external memory; and a power management unit which is arranged to receive a wake up signal, then to first wake up the memory controller; and secondly at a later time to wake up the processor.

Abstract: A method and apparatus for executing an application program stored in an one-time-programmable, OTP, memory in a system on chip (SoC) is described. The SoC has RAM, a CPU and an OTP controller. The OTP memory stores an application program. The method includes, by the processor unit at power-up, instructing the OTP controller to copy the application program from the OTP memory to RAM, executing the application program from RAM, and setting the system on chip (SoC) in sleep mode. By the OTP controller after a wake-up, copying the application program from the OTP memory to the RAM and after the copying, waking up the CPU and transferring control back to the CPU. By the CPU after being woken up by the OTP controller, executing the application program from RAM.

Abstract: An integrated circuit with a patching function comprises a one-time programmable memory (OTP), a random access memory (RAM), and a control unit. The control unit copies data stored on the OTP into the RAM to obtain a copied image mirroring said data. It checks for presence of one or more patch instructions in the OTP, and, if a patch instruction is found in the OTP, modifies a portion of the copied image based on the patch instruction, to obtain a patched image stored in the RAM. The integrated circuit further comprises a processing unit configured to access the patched image in the RAM. The patch can be provided wirelessly.

Abstract: Methods and apparatus are provided for authenticated hierarchical set operations. A third party server processes a query (possibly from a client) on data sets outsourced by a source of the data. The query comprises a hierarchical set operation between at least two of the data sets. Authenticated Set Operation techniques for flat set operations can be iteratively applied for hierarchical set operations. In addition, bilinear accumulators are extended to provide an extractable accumulation scheme comprising a primary bilinear accumulator and a secondary bilinear accumulator. The client receives (i) an encoding of an answer to the query, (ii) a verification comprising, for example, one or more of subset witnesses, completeness witnesses, and/or accumulation values, and (iii) at least one argument for at least one intersection operation, union operation and/or set difference operation.

Abstract: Methods and apparatus are provided for authenticated hierarchical set operations. A third party server processes a query q (possibly from a client) on outsourced data sets S1, . . . , Sn on behalf of a source of the data. The query q comprises a hierarchical set operation. Authenticated Set Operation techniques for flat set operations can be iteratively applied for hierarchical set operations. In addition, bilinear accumulators are extended to provide an extractable accumulation scheme comprising a primary bilinear accumulator and a secondary bilinear accumulator. In addition, a query q is parsed as a tree and for each tree node, a Union/Intersection argument is provided that is related to one or more accumulation values associated with the corresponding tree node.

Abstract: A method and apparatus for executing an application program stored in an one-time-programmable, OTP, memory in a system on chip (SoC) is described. The SoC has RAM, a CPU and an OTP controller. The OTP memory stores an application program. The method includes, by the processor unit at power-up, instructing the OTP controller to copy the application program from the OTP memory to RAM, executing the application program from RAM, and setting the system on chip (SoC) in sleep mode. By the OTP controller after a wake-up, copying the application program from the OTP memory to the RAM and after the copying, waking up the CPU and transferring control back to the CPU. By the CPU after being woken up by the OTP controller, executing the application program from RAM.

Abstract: An integrated circuit with a patching function comprises a one-time programmable memory (OTP), a random access memory (RAM), and a control unit. The control unit copies data stored on the OTP into the RAM to obtain a copied image mirroring said data. It checks for presence of one or more patch instructions in the OTP, and, if a patch instruction is found in the OTP, modifies a portion of the copied image based on the patch instruction, to obtain a patched image stored in the RAM. The integrated circuit further comprises a processing unit configured to access the patched image in the RAM. The patch can be provided wirelessly.