Microsoft Technology Licensing, LLC

Microsoft Corporation

Jonathan E Lange

Mehmet Iyigun

Ling Tony Chen

Yevgeniy Bak

Eric Oliver Mejdrich

Jason Matthew Cahill

Brian Lloyd Schmidt

Jon Marcus Randall Whitten

John Victor Sell

Christopher Michael Pirich

Tracy Sharpe

Timothy R Osborne

Jeffrey Edward Simon

Sing Bing Kang

Arun Upadhyaya Kishan

Yasser Baseer Asmi

Robert Matthew Craig

Xin Zhang

Kenneth Dean Johnson

David Hepkin

David Bradley Probert, Jr

Bruce John Sherwin, Jr

Kevin Michael Broas

Eric H Michelman

Arsalan Ahmad

Dax H Hawkins

Michael Bishop Ebersol

Jin Lin

Wen Jia Liu

Greg M Zaverucha

Jonathan G Thomason

Keith K Lau

Joe Bertolami

Alexander Daniel Grest

Jeff Engel

Stephanie Sumyi Luck

Joseph David Barnett

John V Sell

Jonathan Gerald Thomason

Tracy Clayton Sharpe

Isolating resources of a virtual machine (VM) guest from a host operating system. A computer system receives an acceptance request from a guest partition corresponding to an isolated VM. The acceptance request identifies a guest memory page that is mapped into a guest physical address space of the guest partition, and a memory page visibility class. The computer system determines whether a physical memory page that is mapped to the guest memory page meets the memory page visibility class. The computer system sets a page acceptance indication for the guest memory page from an unaccepted state to an accepted state based on the physical memory page meeting the memory page visibility class.

Software isolation of virtual machine resources

To increase the speed with which a Second Layer Address Table (SLAT) is traversed, memory having the same access permissions is contiguously arranged such that one or more hierarchical levels of the SLAT need not be referenced, thereby resulting in more efficient SLAT traversal. 'Slabs' of memory are established whose memory range is sufficiently large that reference to a hierarchically lower level table can be skipped and a hierarchically higher level table's entries can directly identify relevant memory addresses. Such slabs are aligned to avoid smaller intermediate memory ranges. The loading of code or data into memory is performed based on a next available memory location within a slab having equivalent access permissions, or, if such a slab is not available, or if an existing slab does not have a sufficient quantity of available memory remaining, a new slab with the proper access permissions is established.

Faster computer memory access by reducing SLAT fragmentation

Preventing the observation of the side effects of mispredicted speculative execution flows using restricted speculation. In an embodiment a microprocessor comprises a register file including a plurality of entries, each entry comprising a value and a flag. The microprocessor (i) sets the flag corresponding to any entry whose value results from a memory load operation that has not yet been retired or cancelled, or results from a calculation that was derived from a register file entry whose corresponding flag was set, and (ii) clears the flag corresponding to any entry when the operation that generated the entry's value is retired. The microprocessor also comprises a memory unit that is configured to hold any memory load operation that uses an address whose value is calculated based on a register file entry whose flag is set, unless all previous instructions have been retired or cancelled.

Speculative side-channel attack mitigations

A protected machine. The machine includes an enclave. An enclave includes a protected area of an application address space for which access is prevented for any application code not resident in the enclave itself, except that keys can be provided by one or more management enclaves into the enclave. The machine further includes a management enclave coupled to the enclave. The management enclave is configured to provide a key to the enclave. The management enclave is a protected area of an application address space for which access is prevented for any application code not resident in the management enclave itself.

Secure key management

The subject disclosure is directed towards using one or more of hardware, a hypervisor, and privileged mode code to prevent system mode code from accessing user mode data and/or running user mode code at the system privilege level, or vice-versa. Also described is (in systems with a hypervisor) preventing non-hypervisor code from running in hypervisor mode or accessing hypervisor-only data, or vice-versa. A register maintained by hardware, hypervisor, or system mode code contains data access and execution polices for different chunks of addressable space with respect to which requesting entities (hypervisor mode code, system mode code, user mode code) have access to or can execute code in a given chunk. When a request to execute code or access data with respect to an address is received, the request is processed to determine to which chunk the address corresponds. The policy for that chunk is evaluated to determine whether to allow or deny the request.

Secure privilege level execution and access protection

Return oriented programming (ROP) attack prevention techniques are described. In one or more examples, a method is described of protecting against return oriented programming attacks. The method includes initiating a compute signature hardware instruction of a computing device to compute a signature for a return address and the associated location on the stack the return address is stored and causing storage of the computed signature along with the return address in the stack. The method also includes enforcing that before executing the return instruction using the return address on the stack, initiating a verify signature hardware instruction of the computing device to verify the signature matches the target return address on the stack and responding to successful verification of the signature through execution of the verify signature hardware instruction by the computing device, executing the return instruction to the return address.

Return oriented programming (ROP) attack protection

Various embodiments provide techniques and devices for protecting application secrets from operating system attacks. In some examples, applications execute with an isolated user mode of a secure execution environment, while relying on an operating system executing within a separate execution environment for resource management and system services. A proxy kernel can control access by the operating system to data associated with the secure execution environment. Further, the proxy kernel can act as a transparent interface between isolated user mode applications and the operating system during the provision of resource management and system services.

Protecting application secrets from operating system attacks

Game data is rendered in three dimensions in the GPU of a game console. A left camera view and a right camera view are generated from a single camera view. The left and right camera positions are derived as an offset from a default camera. The focal distance of the left and right cameras is infinity. A game developer does not have to encode dual images into a specific hardware format. When a viewer sees the two slightly offset images, the user's brain combines the two offset images into a single 3D image to give the illusion that objects either pop out from or recede into the display screen. In another embodiment, individual, private video is rendered, on a single display screen, for different viewers. Rather than rendering two similar offset images, two completely different images are rendered allowing each player to view only one of the images.

Three dimensional rendering of display information using viewer eye coordinates

A software tool automatically places files and folders of a software program within segments of a DVD. The segments are defined by security placeholders, and the disposition of the placeholders is initially randomly determined, consistent with predefined rules. The placeholders are included on the disc to hinder unauthorized copying. A developer generally defines the order in which the files and folders are to be laid out, and the software tool automatically places the files and folders, filling successive segments and shifting the placeholders to accommodate files that will not fit in a current segment. However, any movement of the placeholders must be done by the tool and is only permitted if the new disposition of the placeholder is in accord with the predefined rules. A user can manually modify the automated layout, and in response, the files and folders are automatically shifted to accommodate the changes introduced by the user.

Game disk layout

Cache management strategies are described for retrieving information from a storage medium, such as an optical disc, using a cache memory including multiple cache segments. A first group of cache segments can be devoted to handling the streaming transfer of a first type of information, and a second group of cache segments can be devoted to handling the bulk transfer of a second type of information. A host system can provide hinting information that identifies which group of cache segments that a particular read request targets. A circular wrap-around fill strategy can be used to iteratively supply new information to the cache segments upon cache hits by performing pre-fetching. Various eviction algorithms can be used to select a cache segment for flushing and refilling upon a cache miss, such as a least recently used (LRU) algorithm or a least frequently used (LFU) algorithm.

Strategies for reading information from a mass storage medium using a cache memory

Authenticity of digital data, security policies, and usage of game software are enforced on a game console. When the software is secured prior to distribution on media, a private key is used to encrypt a header digest that includes a digest of each section of the software and information specifying a region, a rating, and media type of the software. A hashing algorithm is applied to produce the digests. On the game console, a public key is used to decrypt the header digest for comparison to a hash of the header. A digest of each section of digital data is computed and compared to the corresponding digest in the header to authenticate the data. The console will not execute the software unless the parameters in the header information match those stored in the console and the computed digests for each section match those in the header on the medium.

Secure digital data format and code enforced policy

A data protection portion includes the file alteration checking portion. One aspect of the file alteration checking portion relates to a media including game content and a data protection portion. In one version, the data protection portion protects the game content from modification by determining whether the game content has been modified. If the game content has been modified, then the installation of the game content within the apparatus fails.

Media data protection with secure installer

Growing community of inventors

Bellevue, WA, United States of America

Jonathan E Lange