Patents Assigned to GRAPHCORE LTD.
  • Patent number: 11651090
    Abstract: A method for securely terminating a distributed trusted execution environment (TEE) spanning a plurality of work accelerators. After wiping sensitive data from the memory of its accelerator, a root of trust for each accelerator is configured to receive confirmation that the data has been wiped from the processor memory in relevant other accelerators prior to moving on to the next stage at which the TEE on its associated accelerator is terminated. Since the data has been wiped from the other accelerators, even if a third party were to inject malicious code into the accelerator, they would be unable to read out the secret data from the other accelerators since the data has been wiped from those other accelerators. In this way, a mechanism is provided for ensuring that when the distributed TEE is terminated, malicious third parties are unable to read out confidential data from the accelerators.
    Type: Grant
    Filed: July 13, 2021
    Date of Patent: May 16, 2023
    Assignee: GRAPHCORE LTD.
    Inventors: Daniel John Pelham Wilkinson, Stavros Volos, Kapil Vaswani, Balaji Vembu
  • Patent number: 11651089
    Abstract: A method for securely terminating a distributed trusted execution environment spanning a plurality of work accelerators. Each accelerator is configured to self-isolate upon determining that the distributed TEE is to be terminated across the system of accelerators. The data is also wiped from the processor memory of each accelerator, such that the data cannot be read out from the processor memory once the accelerator's links are re-enabled. The self-isolation is performed on each accelerator prior to the step of terminating the TEE on that accelerator. An accelerator only re-enables its links to other accelerators once the data is wiped from its processor memory such that the secret data is removed from the accelerator memory.
    Type: Grant
    Filed: July 13, 2021
    Date of Patent: May 16, 2023
    Assignee: GRAPHCORE LTD.
    Inventors: Daniel John Pelham Wilkinson, Stavros Volos, Kapil Vaswani, Balaji Vembu