Other

Arm Limited

Jonathan Sean Callan

Keir Finlow-Bates

David Hennah Mansell

Christopher Pedley

David James Seal

Luc Orion

Simon Charles Watt

Nicolas Chaussade

Lionel Belnet

Christopher Bentley Dornan

Stephane Eric Sebastien Brochier

Hedley James Francis

A data management blockchain and protocol for controlling access to data, in which no central trusted authority is required, is presented. The data management blockchain and protocol comprises an initial announcement of public keys by a plurality of blockchain participants, through which each blockchain participant establishes an identity. Subsequently a first of the plurality of blockchain participants publishes data encrypted with a cryptographic key on the blockchain. A second of the plurality of blockchain participants is assigned as an owner of the data by an authority. Access to the data is granted or revoked to further participants by the second of the plurality of blockchain participants through signed permission messages published on the blockchain, and a corresponding hand-over of the cryptographic key by the first of the plurality of blockchain participants, allowing access to the data. Access to further data may be revoked by changing the cryptographic key used.

Method and system for managing decentralized data access permissions through a blockchain

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.

System and method for enforcing the structure and content of databases synchronized over a distributed ledger

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.

Blockchain based digital certificate provisioning of internet of things devices

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.

System and method for storing the location on a blockchain of a hash of a digital item within said digital item

Monitoring logicfor monitoring a data processorto detect if it is not operating as anticipated, the monitoring logiccomprising: a timeroperable to measure a predetermined time; detection logic; and control logic; wherein said detection logic is operable to detect a data or instruction access to at least one predetermined address and in response to not detecting said data or instruction access within said predetermined time, said control logic is operable to send a control signal to said data processor, said control signal controlling said data processor to perform a predetermined operation.

Monitoring a data processor to detect abnormal operation

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.

Apparatus and method for generating constant values

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.

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Cambridge, United Kingdom

Jonathan Sean Callan