公开(公告)号：US09292712B2

公开(公告)日：2016-03-22

申请号：US13630222

申请日：2012-09-28

Applicant: ST-Ericsson SA

Inventor： Per Ståhl ,  Håkan Englund ,  Martin Hovang ,  Hervé Sibert

IPC: G06F1/00 ,  G06F21/72 ,  G06F1/14 ,  G06F21/74

CPC classification number: G06F21/725 ,  G06F1/14 ,  G06F21/74

Abstract: An exemplary method of maintaining secure time in a computing device is disclosed in which one or more processors implements a Rich Execution Environment (REE), and a separate Trusted Execution Environment (TEE). The TEE maintains a real-time clock (RTC) that provides a RTC time to the REE. A RTC offset is stored in non-volatile memory, with the RTC offset indicating a difference between the RTC time and a protected reference (PR) time. Responsive to a request from the REE to read the RTC time, a current RTC time is returned to the REE. Responsive to a request from the REE to adjust the RTC time, the RTC time and the corresponding RTC offset are adjusted by a same amount, such that the PR time is not altered by the RTC adjustment. An exemplary computing device operable to implement the method is also disclosed.

Abstract translation: 公开了一种在计算设备中维护安全时间的示例性方法，其中一个或多个处理器实现富执行环境（REE）和单独的可信执行环境（TEE）。 TEE维护一个实时时钟（RTC），为REE提供RTC时间。 RTC偏移量存储在非易失性存储器中，RTC偏移指示RTC时间和受保护参考（PR）时间之间的差异。 响应REE阅读RTC时间的请求，当前的RTC时间将返回给REE。 响应于REE调整RTC时间的请求，RTC时间和相应的RTC偏移量调整相同的量，使得PR时间不被RTC调整改变。 还公开了可操作以实现该方法的示例性计算设备。