Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A computer system has a separation mechanism which enforces separation between at least two execution environments such that one execution environment is a gatekeeper which interposes on all communications of the other execution environment. The computer system has an attestation mechanism which enables the gatekeeper to attest to properties of the at least two execution environments. A first one of the execution environments runs application specific code which may contain security vulnerabilities. The gatekeeper is configured to enforce an input output policy on the first execution environment by interposing on all communication to and from the first execution environment by forwarding, modifying or dropping individual ones of the communications according to the policy. The gatekeeper provides evidence of attestation both for the application specific code and the policy.

Abstract: 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. The method comprises using an immutable firmware layer 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A computer system has a separation mechanism which enforces separation between at least two execution environments such that one execution environment is a gatekeeper which interposes on all communications of the other execution environment. The computer system has an attestation mechanism which enables the gatekeeper to attest to properties of the at least two execution environments. A first one of the execution environments runs application specific code which may contain security vulnerabilities. The gatekeeper is configured to enforce an input output policy on the first execution environment by interposing on all communication to and from the first execution environment by forwarding, modifying or dropping individual ones of the communications according to the policy. The gatekeeper provides evidence of attestation both for the application specific code and the policy.

Abstract: 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.