摘要:
A data processing apparatus is operable in a plurality of modes and in either a secure domain or a non-secure domain. When operating in a secure mode within the secure domain a program has access to secure data which is not accessible when the processor is operating in a non-secure mode. A vectored interrupt controller is provided to generate an exception handler address in response to an occurrence of an except condition. The vectored interrupt controller is programmable with parameters specifying for each exception condition whether an exception handler in the secure or the non-secure domain should be triggered and an exception handler address for use if the exception occurs when in the appropriate domain. The vectored interrupt controller also includes a parameter specifying a domain switching exception handler address for use if the exception condition occurs when the processor is not in the appropriate domain.
摘要:
A data processing apparatus and method for generating constant values is provided. The data processing apparatus comprises a data processing unit operable in response to an instruction to perform a data processing operation on one or more data values. Shift logic is operable to selectively apply a shift operation to data to produce one of the data values for the data processing operation. Further, a plurality of registers are provided for storing data. The instruction has a register specifier field for identifying a register and a shift specifier field for specifying a shift to be applied to that register's data in order to produce one of the data values for the data processing operation. The register specifier field is allocatable a distinguished value, and if the register specifier field has that distinguished value, the shift logic is provided with a predetermined value and generates therefrom one of a plurality of constant values dependent on the shift specified by the shift specifier field, the generated constant value then being used as one of the data values for the data processing operation.
摘要:
A system and method for provisioning an IoT device with a digital certificate without a need for a central Certificate Authority is presented. A blockchain is initiated, with a root certificate presented in an initial block of the blockchain. Said root certificate is subsequently used to sign an authorized certificate. The IoT device is preloaded with a nonce, and a hash of the nonce signed by an authorized certificate is published on the blockchain. The nonce may then be submitted to the blockchain with a self-signed certificate, the presence of the nonce validating the self-signed certificate. The blockchain provides a final single view of a true state of the digital certificates in the system and their respective authority and validity.
摘要:
A system and method for provisioning an IoT device with a digital certificate without a need for a central Certificate Authority is presented. A blockchain is initiated, with a root certificate presented in an initial block of the blockchain. Said root certificate is subsequently used to sign an authorized certificate. The IoT device is preloaded with a nonce, and a hash of the nonce signed by an authorized certificate is published on the blockchain. The nonce may then be submitted to the blockchain with a self-signed certificate, the presence of the nonce validating the self-signed certificate. The blockchain provides a final single view of a true state of the digital certificates in the system and their respective authority and validity.
摘要:
A system and method for provisioning an IoT device with a digital certificate without a need for a central Certificate Authority is presented. A blockchain is initiated, with a root certificate presented in an initial block of the blockchain. Said root certificate is subsequently used to sign an authorized certificate. The IoT device is preloaded with a nonce, and a hash of the nonce signed by an authorized certificate is published on the blockchain. The nonce may then be submitted to the blockchain with a self-signed certificate, the presence of the nonce validating the self-signed certificate. The blockchain provides a final single view of a true state of the digital certificates in the system and their respective authority and validity.
摘要:
A system and method is presented for storing a location on a blockchain of a hash, such as a cryptographic hash, digital fingerprint, or digest, of a digital item, such as a document, file, sound clip, or computer code, within the digital item itself. The blockchain may be used for providing a provenance of the digital item by generating the hash of the digital item and submitting it within a transaction to the blockchain. The system and method presented allow the location of the hash within the blockchain to be embedded within the digital item before said hash is generated and submitted, providing a clear link between a record of the hash and the digital item in question, and reducing the computational and network resources required to verify the provenance of the digital item.
摘要:
A method and system is presented for reaching consensus on adding data to and extending the structure or schema of databases synchronized across a distributed ledger or blockchain system, in which no central trusted authority is available, comprising sending an announcement message by a network connected device to a plurality of network connected devices over a network, said message proposing a database schema change or extension. If the announcement message and preceding data in the distributed ledger satisfy predetermined conditions, the plurality of network connected devices may include the data in the distributed ledger, and modify the schema of their databases in a corresponding manner. If data is submitted that requires a structural change to the database before the announcement message has been incorporated in the distributed ledger, the data is rejected by the network and is not included in the distributed ledger.
摘要:
A data processing apparatus is described which comprises a processor operable to execute a sequence of instructions and a cache memory having a plurality of cache lines operable to store data values for access by the processor when executing the sequence of instructions. A cache controller is also provided which comprises preload circuitry operable in response to a streaming preload instruction received at the processor to store data values from a main memory into one or more cache lines of the cache memory. The cache controller also comprises identification circuitry operable in response to the streaming preload instruction to identify one or more cache lines of the cache memory for preferential reuse. The cache controller also comprises cache maintenance circuitry operable to implement a cache maintenance operation during which selection of one or more cache lines for reuse is performed having regard to any preferred for reuse identification generated by the identification circuitry for cache lines of the cache memory. In this way, a single streaming preload instruction can be used to trigger both a preload of one or more cache lines of data values into the cache memory, and also to mark for preferential reuse another one or more cache lines of the cache memory.
摘要:
A method and system is presented for reaching consensus on adding data to and extending the structure or schema of databases synchronized across a distributed ledger or blockchain system, in which no central trusted authority is available, comprising sending an announcement message by a network connected device to a plurality of network connected devices over a network, said message proposing a database schema change or extension. If the announcement message and preceding data in the distributed ledger satisfy predetermined conditions, the plurality of network connected devices may include the data in the distributed ledger, and modify the schema of their databases in a corresponding manner. If data is submitted that requires a structural change to the database before the announcement message has been incorporated in the distributed ledger, the data is rejected by the network and is not included in the distributed ledger.
摘要:
Descriptions of time altering apparatuses for removing a need for leap seconds are provided. Currently leap seconds are applied to Universal Time Coordinated (UTC) in order to align UTC with mean solar time. In one embodiment a time measurement system is connected to a gigantic heavy flywheel positioned at at least one of a north rotational pole or south rotational pole of the Earth. The time measurement system may determine a shift of UTC away from mean solar time and may subsequently speed up or slow down the flywheel to adjust a rotational speed of the Earth in order to move UTC back to mean solar time. In a second embodiment a similar time measurement system may raise or lower heavy weights into mine shafts drilled at or near the equator of the Earth for a similar effect. Planetary speed adjustments may be written to a blockchain.