Microsoft Technology Licensing, LLC

Graphcore Limited

Stavros Volos

Kapil Vaswani

Daniel John Pelham Wilkinson

Cédric Alain Marie Fournet

Manuel Costa

Graham Bernard Cunningham

Samuel Alexander Webster

Balaji Vembu

Saurabh Mohan Kulkarni

David Thomas Chisnall

Richard William Osborne

Simon Douglas Chambers

Colin Doak

Richard Neal

David Ruggles

Kenneth Gordon

John Andrew Starks

Ganesh Ananthanarayanan

Sylvan Wesley Clebsch

Sean A Allen

Srinath T V Setty

Rishabh Poddar

Antonio Nino Diaz

A peripheral device, for use with a host, comprises one or more compute elements a security module and at least one encryption unit. The security module is configured to form a trusted execution environment on the peripheral device for processing sensitive data using sensitive code. The sensitive data and sensitive code are provided by a trusted computing entity which is in communication with the host computing device. The at least one encryption unit is configured to encrypt and decrypt data transferred between the trusted execution environment and the trusted computing entity via the host computing device. The security module is configured to compute and send an attestation to the trusted computing entity to attest that the sensitive code is in the trusted execution environment.

Peripheral device

A processing system comprising one or more chips, each comprising a plurality of tiles is described. Each tile comprises a respective processing unit and memory, the memory storing a codelet. The processing system has at least one encryption unit configured to encrypt and decrypt data transferred between the tiles and a trusted computing entity via an external computing device. The codelets are configured to instruct the tiles to transfer the encrypted data by reading from and writing to a plurality of memory regions at the external memory such that a plurality of streams of encrypted data are formed, each stream using an individual one of the memory regions at the external computing device.

Streaming data to multi-tile processing system

In various examples, there is a method of enabling an attestable update of a firmware layer that provides a unique identity of a computing device. An immutable firmware layer is used to access a unique device secret. The immutable layer is used to derive a hardware device identity (HDI) from the unique device secret. The immutable layer is used to derive a compound device identity (CDI) from a measurement of the firmware layer and the unique device secret. The CDI and HDI are made available to the firmware layer. The firmware layer is used to issue a local certificate to endorse a device identity key, derived from the CDI, the local certificate signed by a key derived from the HDI.

Attesting update of a firmware layer

In various examples there is a computing device comprising: a first microcontroller comprising a first immutable bootloader and first mutable firmware. The first immutable bootloader uses a unique device secret burnt into hardware of the computing device in order to generate an attestation of the first mutable firmware. The computing device has a second microcontroller. There is second mutable firmware at the second microcontroller. There is a second immutable bootloader at the second microcontroller which sends a measurement of the second mutable firmware to the first immutable bootloader whenever the second microcontroller restarts, such that the first microcontroller is able to include the measurement in the attestation.

Measured restart of microcontrollers

A system and method for encrypting and decrypting data exchanged between a multi-tile processing unit and a storage, where a plurality of keys are used for the encryption. Each of the plurality of keys is associated with a different one or more sets of the processors. Encryption hardware is configured to select a key to use for encryption/decryption operations in dependence upon the set of tiles associated with the data being exchanged. Each write request from a tile contains identifier bits associated with that tile's set of tiles, enabling the encryption hardware to select the key to use for encrypting the data in the write request. Each read completion for a tile contains identifier bits associated with that tile's set of tiles, enabling the encryption hardware to select the key to use for decrypting the data in the read completion.

Multiple key management

A system comprising a hosting service configured to perform: providing, to a trusted entity on a central processing unit, a command for a launch of a virtual machine (VM); assigning, to the VM, at least a portion of memory for the guest operating system; submitting, to the trusted entity, a request to measure an address space of the VM to provide a measurement digest of the address space of the guest operating system; including, in a configuration object, a policy provided by the user for the service logic, wherein the policy defines one or more rules for the service logic, wherein the one or more rules include at least one rule for which containers may run in the guest operating system; hashing the policy to provide a hash digest of the policy; submitting, to the trusted entity, the hash digest of the policy; and completing the launch of the VM.

Secure computing mechanism

A peripheral device package for use in a host computing device has a plurality of compute elements and a plurality of resources shared by the plurality of compute elements. A datastructure is stored in a hidden memory of the peripheral device package. The data structure holds metadata about ownership of resources of the peripheral device package by a plurality of user runtime processes of the host computing device which use the compute elements. At least one of the user runtime processes is a secure user runtime process. The peripheral device package has a command processor configured to use the datastructure to enforce isolation of the resources used by the secure user runtime process.

Peripheral device with resource isolation

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.

Terminating distributed trusted execution environment via confirmation messages

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.

Terminating distributed trusted execution environment via self-isolation

This document relates to performing video analytics on a cloud device that preserves privacy. One example uses data-oblivious algorithms to process input video data, where the data-oblivious algorithms can assist with preventing attackers from exploiting side-channels induced by data-dependent access patterns.

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Cambridge, United Kingdom

Stavros Volos