Microsoft Technology Licensing, LLC

Other

David Thomas Chisnall

Sylvan Wesley Clebsch

Manuel Costa

Samuel Alexander Webster

Cédric Alain Marie Fournet

Stavros Volos

Saurabh Mohan Kulkarni

Nathaniel Wesley Filardo

Robert McNeill Norton-wright

Daniel John Pelham Wilkinson

Kapil Vaswani

Graham Bernard Cunningham

Richard William Osborne

Matthew John Parkinson

Cédric Alain Marie Christophe Fournet

Roy Schuster

Hongyan Xia

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 hardware revocation engine for invalidating a pointer, that refers to a deallocated object, from memory in a memory constrained system. The hardware revocation engine has a revocation pipeline coupled to a pipeline of a main processor of the memory constrained system. The revocation pipeline shares access to memory with the main pipeline, the revocation pipeline comprising at least a first stage and a subsequent second stage. In a first cycle of the revocation pipeline, the first stage of the revocation pipeline loads a first pointer-sized value from the memory. In a second cycle: the second stage checks whether the first loaded pointer-sized value is a pointer referring to deallocated memory. In a third cycle: in response to the outcome of the check indicating that the first loaded pointer-sized value is a pointer referring to deallocated memory, the first stage invalidates the first pointer-sized value.

Hardware revocation engine for temporal memory safety

In examples there is a computing device comprising a processor, the processor having a memory management unit. The computing device also has a memory that stores instructions that, when executed by the processor, cause the memory management unit to receive a memory access instruction comprising a virtual memory address; translate the virtual memory address to a physical memory address of the memory, and obtain permission information associated with the physical memory address. Responsive to the permission information indicating that metadata is permitted to be associated with the physical memory address, a check is made of a metadata summary table stored in the physical memory to check whether metadata is compatible with the physical memory address. Responsive to the check being unsuccessful, a trap is sent to system software of the computing device in order to trigger dynamic allocation of physical memory for storing metadata associated with the physical memory address.

Dynamically allocatable physically addressed metadata storage

A method of memory deallocation across a trust boundary between a first software component and a second software component is described. Some memory is shared between the first and second software components. An in-memory message passing facility is implemented using the shared memory. The first software component is used to deallocate memory from the shared memory which has been allocated by the second software component. The deallocation is done by: taking at least one allocation to be freed from the message passing facility; and freeing the at least one allocation using a local deallocation mechanism while validating that memory access to memory owned by data structures related to memory allocation within the shared memory are within the shared memory.

Memory deallocation across a trust boundary

According to a first aspect, execution logic is configured to perform a linear capability transfer operation which transfers a physical capability from a partition of a first software modules to a partition of a second of software module without retaining it in the partition of the first. According to a second, alternative or additional aspect, the execution logic is configured to perform a sharding operation whereby a physical capability is divided into at least two instances, which may later be combined.

System for confidential computing with capabilities

Confidential computing mechanism

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.

Execution environment and gatekeeper arrangement

A shutter assembly includes a structure which surrounds an opening and a shutter including a plurality of laths hingedly connected together at their longitudinal edges and moveable across the opening in a direction substantially normal to those longitudinal edges between an opened position and a closed position to respectively open and close the opening. A latch mechanism is operable to retain the shutter in the closed position. The latch mechanism includes at least one latch member mounted on the shutter and, for each latch member, at least one keeper mounted on the structure and which has a portion with which the respective latch member may be engaged to latch the shutter in the closed position. A sensor includes an emitter and a detector positioned such that when the latch member is engaged the signal transmitted by the emitter is reflected by the latch member and is received by the detector, and positioned such that when the latch member is not engaged the signal from the emitter is not received by the detector. A related sensor device assembly is also disclosed.

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Cambridge, United Kingdom

David Thomas Chisnall