Apparatuses, methods, and systems for instructions for usage restrictions cryptographically tied with data

    公开(公告)号:US12238217B2

    公开(公告)日:2025-02-25

    申请号:US18589125

    申请日:2024-02-27

    Inventor: Jason W. Brandt

    Abstract: Systems, methods, and apparatuses relating to circuitry to implement an instruction to create and/or use data that is restricted in how it can be used are described. In one embodiment, a hardware processor comprises a decoder of a core to decode a single instruction into a decoded single instruction, the single instruction comprising a first input operand of a handle including a ciphertext of an encryption key (e.g., cryptographic key), an authentication tag, and additional authentication data, and a second input operand of data encrypted with the encryption key, and an execution unit of the core to execute the decoded single instruction to: perform a first check of the authentication tag against the ciphertext and the additional authentication data for any modification to the ciphertext or the additional authentication data, perform a second check of a current request of the core against one or more restrictions specified by the additional authentication data of the handle, decrypt the ciphertext to generate the encryption key only when the first check indicates no modification to the ciphertext or the additional authentication data, and the second check indicates the one or more restrictions are not violated, decrypt the data encrypted with the encryption key to generate unencrypted data, and provide the unencrypted data as a resultant of the single instruction.

    Processor extensions to protect stacks during ring transitions

    公开(公告)号:US12135780B2

    公开(公告)日:2024-11-05

    申请号:US18232810

    申请日:2023-08-10

    Abstract: A processor implementing techniques for processor extensions to protect stacks during ring transitions is provided. In one embodiment, the processor includes a plurality of registers and a processor core, operatively coupled to the plurality of registers. The plurality of registers is used to store data used in privilege level transitions. Each register of the plurality of registers is associated with a privilege level. An indicator to change a first privilege level of a currently active application to a second privilege level is received. In view of the second privilege level, a shadow stack pointer (SSP) stored in a register of the plurality of registers is selected. The register is associated with the second privilege level. By using the SSP, a shadow stack for use by the processor at the second privilege level is identified.

    MICROARCHITECTURAL MECHANISMS FOR THE PREVENTION OF SIDE-CHANNEL ATTACKS

    公开(公告)号:US20220335126A1

    公开(公告)日:2022-10-20

    申请号:US17590470

    申请日:2022-02-01

    Abstract: Systems, methods, and apparatuses relating to microarchitectural mechanisms for the prevention of side-channel attacks are disclosed herein. In one embodiment, a processor includes a core having a plurality of physical contexts to execute a plurality of threads, a plurality of structures shared by the plurality of threads, a context mapping structure to map context signatures to respective physical contexts of the plurality of physical contexts, each physical context to identify and differentiate state of the plurality of structures, and a context manager circuit to, when one or more of a plurality of fields that comprise a context signature is changed, search the context mapping structure for a match to another context signature, and when the match is found, a physical context associated with the match is set as an active physical context for the core.

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