# Patent

## Title
Trusted security zone enhanced with trusted hardware drivers

## Abstract

An electronic device comprises a processor, a permissive sector, a trusted security zone that is separate from the permissive sector, a hardware driver, a first trusted application, stored in the trusted security zone, that is configured to invoke the hardware driver in response to activation instructions, and a second trusted application, stored in the trusted security zone, that when executed on the processor, configures the processor to: amass information about an uncompromised state of the hardware driver, store the information about the uncompromised state of the hardware driver in the trusted security zone, and compare, in response to receipt of activation instructions by the first trusted application, the information about the uncompromised state of the hardware driver with a current state of the hardware driver, and perform an action in response to a result of the comparison.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not applicable.
BACKGROUND
Electronic devices in the future are expected to store or embody a variety of applications that may interact with confidential information such as credit card numbers, bank account numbers, authentication numbers, personal data, medical information, and the like. Additionally, electronic devices may promote users installing after market applications that may be infiltrated by malware such as viruses, Trojans, screen scrapers, keyboard monitors, and other nefarious software and/or firmware.
SUMMARY
In an embodiment, an electronic device is disclosed. The electronic device comprises a processor, a permissive sector, a trusted security zone that is separate from the permissive sector, a hardware driver, and a first trusted application stored in the trusted security zone that is configured to invoke the hardware driver in response to activation instructions. The electronic device further comprises a second trusted application stored in the trusted security zone that, when executed on the processor, configures the processor to: amass information about an uncompromised state of the hardware driver, store the information about the uncompromised state of the hardware driver in the trusted security zone, compare, in response to receipt of activation instructions by the first trusted application, the information about the uncompromised state of the hardware driver with a current state of the hardware driver, and perform an action in response to a result of the comparison.
In an embodiment, a method is disclosed. The method comprises activating an application stored in a trusted security zone of the electronic device, wherein the application is configured to invoke a hardware driver. The method further comprises performing, in response to activating the application, a confidence check of the hardware driver, comparing a current state of the hardware driver with an uncompromised state of the hardware driver stored in the trusted security zone of the electronic device, evaluating, in the electronic device, the integrity of the hardware driver based on the comparing, and performing, by the electronic device, an action in response to the result of the evaluating.
In an embodiment, an electronic device is disclosed. The electronic device comprises a permissive sector, a trusted security zone that is separate from the permissive sector, a trusted version of a hardware driver stored in the trusted security zone, a version of the hardware driver stored in the permissive sector of the electronic device, and a first trusted application stored in the trusted security zone and configured to invoke the hardware driver in response to activation instructions. The electronic device further comprises a second trusted application stored in the trusted security zone and configured to: compare, in response to instructions directing the first trusted application to invoke the version of the hardware driver stored in the permissive sector, the trusted version of the hardware driver with the version of the hardware driver stored in the permissive sector, and enable the electronic device to perform an action in response to a result of the comparison.
These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.



BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts.
FIG. 1 is an illustration of an electronic device according to an embodiment of the disclosure.
FIG. 2 is an illustration of a communication system according to an embodiment of the disclosure.
FIG. 3 is a flow chart of a method according to an embodiment of the disclosure.
FIG. 4 is an illustration of a mobile communication device according to an embodiment of the disclosure.
FIG. 5 is a block diagram of a mobile communication device according to an embodiment of the disclosure.
FIG. 6A is a block diagram of a software architecture of a mobile communication device according to an embodiment of the disclosure.
FIG. 6B is a block diagram of another software architecture according to an embodiment of the disclosure.
FIG. 7 is a block diagram of computer system suitable for implementing the several embodiments of the disclosure.



DETAILED DESCRIPTION
It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed systems and methods may be implemented using any number of techniques, whether currently known or not yet in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, but may be modified within the scope of the appended claims along with their full scope of equivalents.
In an embodiment, an electronic device that implements trusted hardware drivers is described. The electronic device may be a mobile device such as a mobile phone, a personal digital assistant, a media player, or other mobile device that implements hardware drivers. Alternatively, the electronic device may be a desktop computer, a laptop computer, a notebook computer, or other computer that implements hardware drivers. The electronic device comprises a trusted security zone. As described further below, trusted security zones reduce the ability of nefarious applications and/or programs that may have infiltrated the electronic device to read from or write to memory, to read from or write to input/output devices, or to read from or write to communication ports while the subject processor and/or electronic device is executing in the trusted security zone. An application executing in the trusted security zone can have a high level of confidence that an untrusted application is not executing on the electronic device at the same time and hence is prevented from interfering with or monitoring the activities of the application.
In order to interact with peripheral hardware, the electronic device may invoke a corresponding driver. The driver may be a device driver, a hardware driver, or some other driver. It should be understood at the outset that while several embodiments of the present disclosure are discussed with reference to hardware drivers, the use of the term “hardware driver” is not intended to limit the scope of the present disclosure rather, the systems and methods disclosed herein may encompass all manner of drivers configured to facilitate communication between the electronic device and peripheral components.
The electronic device may comprise a plurality of hardware drivers corresponding to a plurality of peripheral hardware components. As is known to one skilled in the art, hardware drivers are software programs that mediate between peripheral hardware and a processor. Hardware drivers may be configured to mediate between a processor of the electronic device and peripheral components including printers, video adaptors, network cards, sound cards, local buses, low bandwidth I/O buses, computer storage devices, digital cameras, key boards, monitors, displays, speakers, mice, and/or other peripheral hardware devices.
In an embodiment, applications executing in the trusted security zone may invoke hardware drivers in order to interact with peripheral hardware components. Hardware drivers may be subject to infiltration or attack by nefarious programs. Thus, allowing a trusted application to invoke a non-trusted hardware driver may compromise the environment of trust afforded by the trusted security zone. In order to preserve the integrity of the trusted security zone, hardware drivers to be invoked by trusted applications may be established in trust or may be verified to be trusted. The electronic device may store a plurality of hardware drivers in the trusted security zone that may be readily invoked by trusted applications. Alternatively, the electronic device may perform a confidence check on hardware drivers stored in a permissive sector and/or in the trusted security zone before allowing them to be invoked by trusted applications.
In an embodiment, the electronic device may perform a confidence check on a hardware driver stored either in the permissive sector or in the trusted security zone in response to activating a trusted application and may respond to a result of the confidence check. If the confidence check indicates that the hardware driver is uncompromised, the electronic device may allow the trusted application to invoke the hardware driver and continue its action. Conversely, if the confidence check indicates that the hardware driver has been compromised, corrupted, or otherwise modified, the electronic device may prevent the trusted application from invoking the hardware driver.
A trusted security zone provides chipsets with a hardware root of trust, a secure execution environment for applications, and secure access to peripherals. A hardware root of trust means the chipset should only execute programs intended by the device manufacturer or vendor and resists software and physical attacks, and therefore remains trusted to provide the intended level of security. The chipset architecture is designed to promote a programmable environment that allows the confidentiality and integrity of assets to be protected from specific attacks. Trusted security zone capabilities are becoming features in both wireless and fixed hardware architecture designs. Providing the trusted security zone in the main mobile device chipset and protecting the hardware root of trust removes the need for separate secure hardware to authenticate the device or user. To ensure the integrity of the applications requiring trusted data, such as a mobile financial services application, the trusted security zone also provides the secure execution environment where only trusted applications can operate, safe from attacks. Security is further promoted by restricting access of non-trusted applications to peripherals, such as data inputs and data outputs, while a trusted application is running in the secure execution environment. In an embodiment, the trusted security zone may be conceptualized as hardware assisted security.
A complete trusted execution environment (TEE) may be implemented through the use of the trusted security zone hardware and software architecture. The trusted execution environment is an execution environment that is parallel to the execution environment of the main mobile device operating system. The trusted execution environment and/or the trusted security zone may provide a base layer of functionality and/or utilities for use of applications that may execute in the trusted security zone. For example, in an embodiment, trust tokens may be generated by the base layer of functionality and/or utilities of the trusted execution environment and/or trusted security zone for use in trusted end-to-end communication links to document a continuity of trust of the communications. For more details on establishing trusted end-to-end communication links relying on hardware assisted security, see U.S. patent application Ser. No. 13/532,588, filed Jun. 25, 2012, entitled “End-to-end Trusted Communications Infrastructure,” by Leo Michael McRoberts, et al., which is hereby incorporated by reference in its entirety. Through standardization of application programming interfaces (APIs), the trusted execution environment becomes a place to which scalable deployment of secure services can be targeted. A device which has a chipset that has a trusted execution environment on it may exist in a trusted services environment, where devices in the trusted services environment are trusted and protected against attacks. The trusted execution environment can be implemented on mobile phones and tablets as well as extending to other trusted devices such as personal computers, servers, sensors, medical devices, point-of-sale terminals, industrial automation, handheld terminals, automotive, etc.
The trusted security zone is implemented by partitioning all of the hardware and software resources of the mobile device into two partitions: a secure partition and a normal partition. Placing sensitive resources in the secure partition can protect against possible attacks on those resources. For example, resources such as trusted software applications may run in the secure partition and have access to hardware peripherals such as a touchscreen or a secure location in memory. Less secure peripherals such as wireless radios may be disabled completely while the secure partition is being accessed, while other peripherals may only be accessed from the secure partition. While the secure partition is being accessed through the trusted execution environment, the main mobile operating system in the normal partition is suspended, and applications in the normal partition are prevented from accessing the secure peripherals and data. This prevents corrupted applications or malware applications from breaking the trust of the device.
The trusted security zone is implemented by partitioning the hardware and software resources to exist in a secure subsystem which is not accessible to components outside the secure subsystem. The trusted security zone is built into the processor architecture at the time of manufacture through hardware logic present in the trusted security zone which enables a perimeter boundary between the secure partition and the normal partition. The trusted security zone may only be manipulated by those with the proper credential and, in an embodiment, may not be added to the chip after it is manufactured. Software architecture to support the secure partition may be provided through a dedicated secure kernel running trusted applications. Trusted applications are independent secure applications which can be accessed by normal applications through an application programming interface in the trusted execution environment on a chipset that utilizes the trusted security zone.
In an embodiment, the normal partition applications run on a first virtual processor, and the secure partition applications run on a second virtual processor. Both virtual processors may run on a single physical processor, executing in a time-sliced fashion, removing the need for a dedicated physical security processor. Time-sliced execution comprises switching contexts between the two virtual processors to share processor resources based on tightly controlled mechanisms such as secure software instructions or hardware exceptions. The context of the currently running virtual processor is saved, the context of the virtual processor being switched to is restored, and processing is restarted in the restored virtual processor. Time-sliced execution protects the trusted security zone by stopping the execution of the normal partition while the secure partition is executing.
The two virtual processors context switch via a processor mode called monitor mode when changing the currently running virtual processor. The mechanisms by which the processor can enter monitor mode from the normal partition are tightly controlled. The entry to monitor mode can be triggered by software executing a dedicated instruction, the Secure Monitor Call (SMC) instruction, or by a subset of the hardware exception mechanisms such as hardware interrupts, which can be configured to cause the processor to switch into monitor mode. The software that executes within monitor mode then saves the context of the running virtual processor and switches to the secure virtual processor.
The trusted security zone runs a separate operating system that is not accessible to the device users. For security purposes, the trusted security zone is not open to users for installing applications, which means users do not have access to install applications in the trusted security zone. This prevents corrupted applications or malware applications from executing powerful instructions reserved to the trusted security zone and thus preserves the trust of the device. The security of the system is achieved at least in part by partitioning the hardware and software resources of the mobile phone so they exist in one of two partitions, the secure partition for the security subsystem and the normal partition for everything else. Placing the trusted security zone in the secure partition and restricting access from the normal partition protects against software and basic hardware attacks. Hardware logic ensures that no secure partition resources can be accessed by the normal partition components or applications. A dedicated secure partition operating system runs in a virtual processor separate from the normal partition operating system that likewise executes in its own virtual processor. Users may install applications on the mobile device which may execute in the normal partition operating system described above. The trusted security zone runs a separate operating system for the secure partition that is installed by the mobile device manufacturer or vendor, and users are not able to install new applications in or alter the contents of the trusted security zone. It is anticipated that implementing trusted hardware drivers will further fortify the trusted security zone against nefarious programs.
Turning now to FIG. 1, an electronic device 102 is described. In an embodiment, the electronic device 102 comprises a memory 106, a radio frequency transceiver (RF XCVR) 108, a processor 110, a plurality of peripheral hardware devices (HW DEV) 134, a permissive sector 150, and a trusted security zone 160. The memory 106 may be partitioned into the permissive sector 150 and the trusted security zone 160. The permissive sector may comprise a plurality of non-trusted applications 112, a plurality of hardware drivers (HW DVR) 132, and/or other non-trusted information. The trusted security zone 160 may comprise a plurality of trusted applications 114, trusted information (INF) 126, a plurality of trusted hardware drivers (HW DVR) 130, and/or other items stored in trust. As discussed hereinabove with reference to trusted security zones, the hardware and software components of the electronic device 102 may be partitioned into permissive sectors and trusted security zones. For example, the processor 110 may be divided into the permissive sector 150 and the trusted security zone 160.
In an embodiment, the processor 110 may be a multi-core processor, for example a dual core or quad core processor, wherein the permissive sector 150 and the trusted security zone 160 reside in separate cores. FIG. 1 shows the processor 110 as a single processor, but it should be understood that the electronic device 102 may comprise multiple processors, and these processors may comprise a substantially similar separation of the permissive sector 150 and the trusted security zone 160. Alternatively, when the electronic device 102 comprises multiple processors, each processor may be designated as being either wholly in the permissive sector 150 or wholly in the trusted security zone 160. Similar to their depiction in the processor 110, the permissive sector 150 and the trusted security zone 160 are depicted as sharing the memory 106 in FIG. 1. The permissive sector 150 and the trusted security zone 160 may occur as separate partitions of a single memory chip, or they may occur in physically separate chips.
In an embodiment, the plurality of hardware drivers 132 and the plurality of trusted hardware drivers 130 may each comprise drivers for a printer, a video adaptor, a network card, a sound card, a local bus, low bandwidth I/O buses, a computer storage device, a digital camera, a key board, a monitor, a display, speakers, mice, and/or other drivers. The plurality of peripheral hardware devices 134 may comprise a printer, a video adaptor, a network card, a sound card, a local bus, a low bandwidth I/O bus, a computer storage device, a digital camera, a key board, a monitor, a display, speakers, mice, and/or other peripheral hardware devices.
In an embodiment, the non-trusted applications 112 may invoke the hardware drivers 132 in order to interact with the peripheral hardware devices 134. In an embodiment, the trusted applications 114 stored in the trusted security zone 160 may also interact with the peripheral hardware devices 134. When one of the trusted applications 114 is activated, activity in the permissive sector 150 ceases until all operations in the trusted security zone 160 terminate in order to limit nefarious programs from breaching the trusted security zone 160. The trusted applications 114 may invoke either the hardware drivers 132 or the trusted hardware drivers 130 to facilitate interaction with the peripheral hardware devices 134. In an embodiment, the trusted applications 114 may make calls in the trusted security zone 160 for access to the trusted hardware drivers 130 in response to receipt of instructions for use of the peripheral hardware devices 134. Alternatively, the trusted applications 114 may invoke the hardware drivers 132 after their integrity is confirmed.
A first trusted application 114 of the trusted applications 114 may be configured to invoke either one of the hardware drivers 132 or one of the trusted hardware drivers 130 in response to activation instructions. Or, in some cases, the first trusted application 114 may be configured to invoke a plurality of the hardware drivers 132 and/or the trusted hardware drivers 130 in response to activation instructions. In an embodiment, the electronic device 102 may perform a confidence check on the hardware drivers 132 and/or the trusted hardware drivers 130 in response to activation of the first trusted application 114 and/or in response to being powered on. The electronic device 102 may be configured to perform the confidence check on the hardware drivers 132 that are to be invoked by the first trusted application 114, the trusted hardware drivers 130 that are to be invoked by the first trusted application 114, all of the hardware drivers 132, or to perform the confidence check on a combination of the hardware drivers 132 and the trusted hardware drivers 130. In an embodiment, the electronic device 102 may be configured to allow the first trusted application 114 to invoke the trusted hardware drivers 130 without performing the confidence check.
The confidence check may comprise performing an error detection action such as a checksum, a bit count of the hardware driver, a cyclic redundancy check, a repetition code check, a horizontal redundancy check, a vertical redundancy check, checking information about a parity bit, checking a digital signature, performing a cryptographic hash function, or performing another type of check configured to evaluate the integrity of the hardware drivers 132 and/or the trusted hardware drivers 130. In an embodiment, a second trusted application 114 of the trusted applications 114 may be configured to amass information about an uncompromised state of the hardware drivers 132 and/or the trusted hardware drivers 130 and store the information as trusted information 126 in the trusted security zone 160 for use when the electronic device 102 performs the confidence check.
The uncompromised state of the hardware drivers 132 and the trusted hardware drivers 130 may be a state that is free from sniffers, malware, Trojans, spyware, viruses, and other nefarious programs. The hardware drivers 132 and the trusted hardware drivers 130 may be obtained in the uncompromised state and have information about their uncompromised state stored, by the second trusted application 114, as trusted information 126 in the trusted security zone 160 of the memory 106 upon their installation in the electronic device 102. Information about the uncompromised state of the hardware drivers 132 and the trusted hardware drivers 130 may comprise information to be used in the confidence check. For example, the information may be information about an error detection action such as a checksum, a bit count of the hardware driver, information about a cyclic redundancy check, information about a repetition code, information about a horizontal redundancy check, information about a vertical redundancy check, information about a parity bit, a digital signature, or information about a cryptographic hash function. In the case of a checksum, the second trusted application 114 may obtain a checksum value for the uncompromised state of the trusted hardware drivers 130 and/or the hardware drivers 132 and store the value in the trusted security zone 160.
In an embodiment, the electronic device 102 may activate the second trusted application 114 to perform the confidence check in response to receipt of activation instructions by the first trusted application 114. The confidence check may comprise comparing the information about the uncompromised state of a hardware driver to be invoked by the first trusted application 114 with a current state of the hardware driver in question, wherein the hardware driver in question may be either one of the hardware drivers 132 or one of the trusted hardware drivers 130. The current state may be the state of the hardware driver in question before it is invoked and after the first trusted application 114 has received activation instructions. The comparison may comprise comparing a checksum value obtained for the uncompromised state of the hardware driver in question with a checksum value obtained for the current state of said hardware driver. Alternatively, the comparison may comprise comparing results of an error detection action performed on the uncompromised state and the current state of the hardware driver in question as described hereinabove with reference to the confidence check or it may comprise comparing results from another error detection action performed by the electronic device 102.
In an embodiment, the electronic device 102 may be configured to respond to a result of the comparison between the current state and the uncompromised state of the hardware driver in question. The response may be to allow the first trusted application 114 to invoke the hardware driver in question in response to the result when the result indicates that the current state of the hardware driver in question corresponds to the uncompromised state of the hardware driver in question. The uncompromised state and the current state of the hardware driver in question may be said to correspond if the comparison indicates that the current state of the hardware driver in question is unaltered from the uncompromised state of the hardware driver in question. In this case, the electronic device 102 may have confidence that the trusted security zone 160 will not be compromised by allowing the first trusted application 114 to invoke the hardware driver in question when the result indicates that the two states of the hardware driver in question correspond.
Alternatively, the electronic device 102 may respond by replacing the current state of the hardware driver in question with the uncompromised state of the hardware driver in question, the electronic device 102 may prevent the first trusted application 114 from invoking the hardware driver in question, and/or prompt the user with options in response to the result when the result indicates that the current state of the hardware driver in question does not correspond to the uncompromised state of the hardware driver in question. The electronic device 102 may enact this response in order to inhibit nefarious programs from corrupting the trusted security zone 160.
Turning now to FIG. 2, a communication system 200 is described. In an embodiment, the communication system 200 comprises the electronic device 102, a base transceiver station (BTS) 104, a wireless access point (AP) 105, a network 116, a trusted server (SVR) 118, and a hardware driver data store (HW DVR DB) 120. The electronic device 102 may access the network 116 through wireless communication with the base transceiver station 104 and/or the wireless access point 105. Additionally, it is contemplated that the electronic device 102 may be hardwired to the network 116. The network 116 may be connected to the trusted server 118 which may be connected to the hardware driver data store 120.
The electronic device 102 may obtain drivers from the hardware driver data store 120. The drivers may be device drivers, hardware driver, or some other form of drivers configured to facilitate communication between the electronic device 102 and peripheral components. The following embodiments will be discussed with reference to hardware drivers, but it should be understood that the embodiments may alternatively implement other drivers as discussed hereinabove. In an embodiment, the electronic device 102 may obtain hardware drivers from the hardware driver data store 120 in a manner that preserves the integrity of the trusted security zone 160. For example, the electronic device 102 may obtain the hardware drivers through end-to-end trusted communications infrastructure as described hereinabove. The hardware drivers may comprise the hardware drivers 132 to be installed in the permissive sector 150 and/or the trusted hardware drivers 130 to be installed in the trusted security zone 160. At the time of installation, the second trusted application 114 may gather information about the uncompromised state of the hardware drivers and store the information in the trusted security zone 160. The information may be information about the error detection action as described hereinabove with reference to FIG. 1. When the hardware drivers are stored in the permissive sector 150, the hardware drivers may be configured for use by both the non-trusted applications 112 and the trusted applications 114. The electronic device 102 may allow the non-trusted applications 112 to invoke the hardware drivers without first verifying the integrity of the hardware drivers; however, in order to preserve the trusted environment, the electronic device 102 will perform the confidence check on the hardware drivers before the trusted applications 114 invoke the hardware drivers.
If the hardware driver to be invoked by one of the trusted applications 114 is determined to be in the uncompromised state, the electronic device 102 may allow the trusted application 114 to invoke the driver and proceed as normal. When the hardware driver to be invoked by the trusted application 114 is determined to be compromised and/or otherwise altered from the uncompromised state, the electronic device 102 may take action to prevent the trusted application 114 from invoking the hardware driver in response to the determination. In an embodiment, the electronic device 102 may arrest the activity of the trusted application 114 and prompt a user with an option to either continue, and risk the integrity of the trusted security zone 160, or abort the activities of the trusted application 114. Alternatively, the electronic device 102 may replace the compromised hardware driver with a new, uncompromised hardware driver taken from the hardware driver data store 120.
In an embodiment, hardware drivers may be obtained from the hardware driver data store 120, and each hardware driver may have a version stored in the permissive sector 150 and a version stored in the trusted security zone 160. A version may be a copy of the hardware driver. The electronic device 102 may be configured to obtain hardware drivers from the hardware driver data store 120, store the hardware drivers in the trusted security zone 160, and copy a version of the hardware drivers stored in the trusted security zone 160 into the permissive sector 150. The trusted applications 114 may be configured to use exclusively trusted versions of the hardware drivers, they may be configured to use exclusively versions of the hardware drivers stored in the permissive sector 150 that have been confirmed to be in the uncompromised state, or they may be configured to use versions of the hardware drivers interchangeably provided that the hardware drivers have been determined to be in the uncompromised state. In an embodiment, when a hardware driver stored in the permissive sector 150 is determined to be compromised and/or otherwise changed from its uncompromised state, the electronic device 102 may copy an uncompromised version of the hardware driver from the trusted security zone 160 to the permissive sector 150 such that the trusted applications 114 may invoke the driver with confidence.
In FIG. 3, a method 300 is described. The method will be discussed with reference to hardware drivers, but it should be understood that the method may alternatively implement device drivers or other drivers as discussed hereinabove with reference to FIG. 2. At block 302, an application that is stored in a trusted security zone of an electronic device and is configured to invoke a hardware driver may be activated. A confidence check on the hardware driver may be performed at block 304 in response to activating the application. The confidence check may comprise activating a second application stored in the trusted security zone that is configured to perform the confidence check as described hereinabove with reference to FIG. 1 and FIG. 2. The integrity of the hardware driver may be evaluated by comparing a current state of the hardware driver to an uncompromised state of the hardware driver stored in the trusted security zone at block 306. In an embodiment, the comparison may be made by the second application stored in the trusted security zone. At block 308, an action may be performed, by the electronic device, in response to the result of the evaluation. The action may be to allow the application to invoke the hardware driver when the result indicates that the hardware driver is in the uncompromised state. Alternatively, the action may be to prevent the application from invoking the hardware driver when the result indicates that the hardware driver is compromised and/or altered from the uncompromised state. The electronic device may replace the current state of the hardware driver with the uncompromised state of the hardware driver. Replacing the current state of the hardware driver with the uncompromised state of the hardware driver may comprise copying a version of the uncompromised state of the hardware driver from the trusted security zone into the permissive sector. The compromised and/or altered hardware driver may then be removed from the electronic device. In an embodiment, the electronic device may prompt a user with an option to either allow the application to invoke the hardware driver or to prevent the application from invoking the hardware driver when the result indicates that the hardware driver is compromised and/or altered from the uncompromised state.
Performing the confidence check on the hardware driver when the application stored in the trusted security zone is activated may help to prevent the trusted security zone from being invaded by nefarious programs. By retaining a secure trusted security zone, the user may experience greater security while operating the electronic device. For example, with the trusted security zone intact, the user may have confidence that credit card information and/or other confidential personal information is not being accessed or viewed by nefarious programs while the user is interacting with such information in the trusted security zone.
FIG. 4 depicts the mobile device 400, which is operable for implementing aspects of the present disclosure, but the present disclosure should not be limited to these implementations. Though illustrated as a mobile phone, the mobile device 400 may take various forms including a wireless handset, a pager, a personal digital assistant (PDA), a gaming device, or a media player. The mobile device 400 includes a display 402 and a touch-sensitive surface and/or keys 404 for input by a user. The mobile device 400 may present options for the user to select, controls for the user to actuate, and/or cursors or other indicators for the user to direct. The mobile device 400 may further accept data entry from the user, including numbers to dial or various parameter values for configuring the operation of the handset. The mobile device 400 may further execute one or more software or firmware applications in response to user commands. These applications may configure the mobile device 400 to perform various customized functions in response to user interaction. Additionally, the mobile device 400 may be programmed and/or configured over-the-air, for example from a wireless base station, a wireless access point, or a peer mobile device 400. The mobile device 400 may execute a web browser application which enables the display 402 to show a web page. The web page may be obtained via wireless communications with a base transceiver station, a wireless network access node, a peer mobile device 400 or any other wireless communication network or system.
FIG. 5 shows a block diagram of the mobile device 400. While a variety of known components of handsets are depicted, in an embodiment a subset of the listed components and/or additional components not listed may be included in the mobile device 400. The mobile device 400 includes a digital signal processor (DSP) 502 and a memory 504. As shown, the mobile device 400 may further include an antenna and front end unit 506, a radio frequency (RF) transceiver 508, a baseband processing unit 510, a microphone 512, an earpiece speaker 514, a headset port 516, an input/output interface 518, a removable memory card 520, a universal serial bus (USB) port 522, an infrared port 524, a vibrator 526, a keypad 528, a touch screen liquid crystal display (LCD) with a touch sensitive surface 530, a touch screen/LCD controller 532, a camera 534, a camera controller 536, and a global positioning system (GPS) receiver 538. In an embodiment, the mobile device 400 may include another kind of display that does not provide a touch sensitive screen. In an embodiment, the DSP 502 may communicate directly with the memory 504 without passing through the input/output interface 518. Additionally, in an embodiment, the mobile device 400 may comprise other peripheral devices that provide other functionality.
The DSP 502 or some other form of controller or central processing unit operates to control the various components of the mobile device 400 in accordance with embedded software or firmware stored in memory 504 or stored in memory contained within the DSP 502 itself. In addition to the embedded software or firmware, the DSP 502 may execute other applications stored in the memory 504 or made available via information carrier media such as portable data storage media like the removable memory card 520 or via wired or wireless network communications. The application software may comprise a compiled set of machine-readable instructions that configure the DSP 502 to provide the desired functionality, or the application software may be high-level software instructions to be processed by an interpreter or compiler to indirectly configure the DSP 502.
The DSP 502 may communicate with a wireless network via the analog baseband processing unit 510. In some embodiments, the communication may provide Internet connectivity, enabling a user to gain access to content on the Internet and to send and receive e-mail or text messages. The input/output interface 518 interconnects the DSP 502 and various memories and interfaces. The memory 504 and the removable memory card 520 may provide software and data to configure the operation of the DSP 502. Among the interfaces may be the USB port 522 and the infrared port 524. The USB port 522 may enable the mobile device 400 to function as a peripheral device to exchange information with a personal computer or other computer system. The infrared port 524 and other optional ports such as a Bluetooth® interface or an IEEE 802.11 compliant wireless interface may enable the mobile device 400 to communicate wirelessly with other nearby handsets and/or wireless base stations.
The keypad 528 couples to the DSP 502 via the interface 518 to provide one mechanism for the user to make selections, enter information, and otherwise provide input to the mobile device 400. Another input mechanism may be the touch screen LCD 530, which may also display text and/or graphics to the user. The touch screen LCD controller 532 couples the DSP 502 to the touch screen LCD 530. The GPS receiver 538 is coupled to the DSP 502 to decode global positioning system signals, thereby enabling the mobile device 400 to determine its position.
FIG. 6A illustrates a software environment 602 that may be implemented by the DSP 502. The DSP 502 executes operating system software 604 that provides a platform from which the rest of the software operates. The operating system software 604 may provide a variety of drivers for the handset hardware with standardized interfaces that are accessible to application software. The operating system software 604 may be coupled to and interact with application management services (AMS) 606 that transfer control between applications running on the mobile device 400. Also shown in FIG. 6A are a web browser application 608, a media player application 610, and JAVA applets 612. The web browser application 608 may be executed by the mobile device 400 to browse content and/or the Internet, for example when the mobile device 400 is coupled to a network via a wireless link. The web browser application 608 may permit a user to enter information into forms and select links to retrieve and view web pages. The media player application 610 may be executed by the mobile device 400 to play audio or audiovisual media. The JAVA applets 612 may be executed by the mobile device 400 to provide a variety of functionality including games, utilities, and other functionality.
FIG. 6B illustrates an alternative software environment 620 that may be implemented by the DSP 502. The DSP 502 executes operating system software 628 and an execution runtime 630. The DSP 502 executes applications 622 that may execute in the execution runtime 630 and may rely upon services provided by the application framework 624. Applications 622 and the application framework 624 may rely upon functionality provided via the libraries 626.
FIG. 7 illustrates a computer system 380 suitable for implementing one or more embodiments disclosed herein. The computer system 380 includes a processor 382 (which may be referred to as a central processor unit or CPU) that is in communication with memory devices including secondary storage 384, read only memory (ROM) 386, random access memory (RAM) 388, input/output (I/O) devices 390, and network connectivity devices 392. The processor 382 may be implemented as one or more CPU chips.
It is understood that by programming and/or loading executable instructions onto the computer system 380, at least one of the CPU 382, the RAM 388, and the ROM 386 are changed, transforming the computer system 380 in part into a particular machine or apparatus having the novel functionality taught by the present disclosure. It is fundamental to the electrical engineering and software engineering arts that functionality that can be implemented by loading executable software into a computer can be converted to a hardware implementation by well known design rules. Decisions between implementing a concept in software versus hardware typically hinge on considerations of stability of the design and numbers of units to be produced rather than any issues involved in translating from the software domain to the hardware domain. Generally, a design that is still subject to frequent change may be preferred to be implemented in software, because re-spinning a hardware implementation is more expensive than re-spinning a software design. Generally, a design that is stable that will be produced in large volume may be preferred to be implemented in hardware, for example in an application specific integrated circuit (ASIC), because for large production runs the hardware implementation may be less expensive than the software implementation. Often a design may be developed and tested in a software form and later transformed, by well known design rules, to an equivalent hardware implementation in an application specific integrated circuit that hardwires the instructions of the software. In the same manner as a machine controlled by a new ASIC is a particular machine or apparatus, likewise a computer that has been programmed and/or loaded with executable instructions may be viewed as a particular machine or apparatus.
The secondary storage 384 is typically comprised of one or more disk drives or tape drives and is used for non-volatile storage of data and as an over-flow data storage device if RAM 388 is not large enough to hold all working data. Secondary storage 384 may be used to store programs which are loaded into RAM 388 when such programs are selected for execution. The ROM 386 is used to store instructions and perhaps data which are read during program execution. ROM 386 is a non-volatile memory device which typically has a small memory capacity relative to the larger memory capacity of secondary storage 384. The RAM 388 is used to store volatile data and perhaps to store instructions. Access to both ROM 386 and RAM 388 is typically faster than to secondary storage 384. The secondary storage 384, the RAM 388, and/or the ROM 386 may be referred to in some contexts as computer readable storage media and/or non-transitory computer readable media.
I/O devices 390 may include printers, video monitors, liquid crystal displays (LCDs), touch screen displays, keyboards, keypads, switches, dials, mice, track balls, voice recognizers, card readers, paper tape readers, or other well-known input devices.
The network connectivity devices 392 may take the form of modems, modem banks, Ethernet cards, universal serial bus (USB) interface cards, serial interfaces, token ring cards, fiber distributed data interface (FDDI) cards, wireless local area network (WLAN) cards, radio transceiver cards such as code division multiple access (CDMA), global system for mobile communications (GSM), long-term evolution (LTE), worldwide interoperability for microwave access (WiMAX), and/or other air interface protocol radio transceiver cards, and other well-known network devices. These network connectivity devices 392 may enable the processor 382 to communicate with the Internet or one or more intranets. With such a network connection, it is contemplated that the processor 382 might receive information from the network, or might output information to the network in the course of performing the above-described method steps. Such information, which is often represented as a sequence of instructions to be executed using processor 382, may be received from and outputted to the network, for example, in the form of a computer data signal embodied in a carrier wave.
Such information, which may include data or instructions to be executed using processor 382 for example, may be received from and outputted to the network, for example, in the form of a computer data baseband signal or signal embodied in a carrier wave. The baseband signal or signal embedded in the carrier wave, or other types of signals currently used or hereafter developed, may be generated according to several methods well known to one skilled in the art. The baseband signal and/or signal embedded in the carrier wave may be referred to in some contexts as a transitory signal.
The processor 382 executes instructions, codes, computer programs, scripts which it accesses from hard disk, floppy disk, optical disk (these various disk based systems may all be considered secondary storage 384), ROM 386, RAM 388, or the network connectivity devices 392. While only one processor 382 is shown, multiple processors may be present. Thus, while instructions may be discussed as executed by a processor, the instructions may be executed simultaneously, serially, or otherwise executed by one or multiple processors. Instructions, codes, computer programs, scripts, and/or data that may be accessed from the secondary storage 384, for example, hard drives, floppy disks, optical disks, and/or other device, the ROM 386, and/or the RAM 388 may be referred to in some contexts as non-transitory instructions and/or non-transitory information.
In an embodiment, the computer system 380 may comprise two or more computers in communication with each other that collaborate to perform a task. For example, but not by way of limitation, an application may be partitioned in such a way as to permit concurrent and/or parallel processing of the instructions of the application. Alternatively, the data processed by the application may be partitioned in such a way as to permit concurrent and/or parallel processing of different portions of a data set by the two or more computers. In an embodiment, virtualization software may be employed by the computer system 380 to provide the functionality of a number of servers that is not directly bound to the number of computers in the computer system 380. For example, virtualization software may provide twenty virtual servers on four physical computers. In an embodiment, the functionality disclosed above may be provided by executing the application and/or applications in a cloud computing environment. Cloud computing may comprise providing computing services via a network connection using dynamically scalable computing resources. Cloud computing may be supported, at least in part, by virtualization software. A cloud computing environment may be established by an enterprise and/or may be hired on an as-needed basis from a third party provider. Some cloud computing environments may comprise cloud computing resources owned and operated by the enterprise as well as cloud computing resources hired and/or leased from a third party provider.
In an embodiment, some or all of the functionality disclosed above may be provided as a computer program product. The computer program product may comprise one or more computer readable storage medium having computer usable program code embodied therein to implement the functionality disclosed above. The computer program product may comprise data structures, executable instructions, and other computer usable program code. The computer program product may be embodied in removable computer storage media and/or non-removable computer storage media. The removable computer readable storage medium may comprise, without limitation, a paper tape, a magnetic tape, magnetic disk, an optical disk, a solid state memory chip, for example analog magnetic tape, compact disk read only memory (CD-ROM) disks, floppy disks, jump drives, digital cards, multimedia cards, and others. The computer program product may be suitable for loading, by the computer system 380, at least portions of the contents of the computer program product to the secondary storage 384, to the ROM 386, to the RAM 388, and/or to other non-volatile memory and volatile memory of the computer system 380. The processor 382 may process the executable instructions and/or data structures in part by directly accessing the computer program product, for example by reading from a CD-ROM disk inserted into a disk drive peripheral of the computer system 380. Alternatively, the processor 382 may process the executable instructions and/or data structures by remotely accessing the computer program product, for example by downloading the executable instructions and/or data structures from a remote server through the network connectivity devices 392. The computer program product may comprise instructions that promote the loading and/or copying of data, data structures, files, and/or executable instructions to the secondary storage 384, to the ROM 386, to the RAM 388, and/or to other non-volatile memory and volatile memory of the computer system 380.
In some contexts, the secondary storage 384, the ROM 386, and the RAM 388 may be referred to as a non-transitory computer readable medium or a computer readable storage media. A dynamic RAM embodiment of the RAM 388, likewise, may be referred to as a non-transitory computer readable medium in that while the dynamic RAM receives electrical power and is operated in accordance with its design, for example during a period of time during which the computer 380 is turned on and operational, the dynamic RAM stores information that is written to it. Similarly, the processor 382 may comprise an internal RAM, an internal ROM, a cache memory, and/or other internal non-transitory storage blocks, sections, or components that may be referred to in some contexts as non-transitory computer readable media or computer readable storage media.
While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented.
Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.

## Claims

1. An electronic device, comprising:
at least one processor that includes:
a normal partition of the at least one processor that is associated with a permissive sector, and
a secure partition of the at least one processor that is associated with a trusted security zone, the trusted security zone providing a hardware root of trust and an operating system for the secure partition that runs separate from a normal partition operating system, wherein the trusted security zone ceases execution of non-trusted applications in the permissive sector during execution of at least one trusted application in the secure partition;
a non-transitory memory that includes:
a normal partition of the non-transitory memory that is associated with the permissive sector, the permissive sector allowing non-trusted applications to invoke hardware drivers stored in the normal partition, and
a secure partition of the non-transitory memory that is associated with the trusted security zone and comprises a trusted version of a hardware driver that provides information about an uncompromised state associated with the hardware driver, wherein the trusted security zone is separate from the permissive sector;
the hardware driver associated with a version that is stored in the non-transitory memory and comprises a current state, wherein the hardware driver is at least initially stored in the normal partition of the non-transitory memory;
a first trusted application, stored in the secure partition of the non-transitory memory associated with the trusted security zone, configured to invoke the hardware driver in response to activation instructions; and
a second trusted application, stored in the secure partition of the non-transitory memory associated with the trusted security zone, that when executed by the secure partition of the at least one processor, configures the secure partition of the at least one processor to:
amass the information about the uncompromised state associated with the hardware driver,
store, in the secure partition of the non-transitory memory, the information about the uncompromised state associated with the hardware driver,
perform, in response to receipt of the activation instructions by the first trusted application, a confidence check on the version of the hardware driver stored in the permissive sector and compare, in response to receipt of the activation instructions by the first trusted application, the trusted version of the hardware driver with the version of the hardware driver stored in the permissive sector and the information about the uncompromised state associated with the hardware driver with the current state of the hardware driver, and
enable, based on the confidence check and in response to a result of the comparison indicating that the version of the hardware driver stored in the permissive sector corresponds with the trusted version of the hardware driver and the current state of the hardware driver corresponds to the uncompromised state associated with the hardware driver, the first trusted application stored and executed in the secure partition of the trusted security zone to invoke the hardware driver, wherein the hardware driver is invoked by the first trusted application responsive to the enablement by the second trusted application.

2. The electronic device of claim 1,
wherein the information about the uncompromised state of the hardware driver is associated with an error detection action, and
wherein the information associated with the error detection action comprises at least one of: a checksum, a bit count of the driver, information about a cyclic redundancy check, information about a repetition code, information about a horizontal redundancy check, information about a vertical redundancy check, information about a parity bit, a digital signature, or information about a cryptographic hash function.

3. The electronic device of claim 1, wherein the uncompromised state is associated with the hardware driver being free from sniffers, malware, Trojans, spyware, viruses, or other nefarious programs.

4. The electronic device of claim 1, wherein the second trusted application further configures the secure partition of the at least one processor to: perform a confidence check on the current state of the driver prior to the comparison of the uncompromised state of the driver with the current state of the driver.

5. The electronic device of claim 1, wherein the current state of the hardware driver corresponds with the uncompromised state responsive to the comparison indicating that the current state is unaltered from the uncompromised state.

6. The electronic device of claim 1, wherein responsive to the comparison indicating that the current state of the hardware driver does not correspond with the uncompromised state, the second trusted application:
replace the hardware driver with another hardware driver that is in the uncompromised state,
prevent the first trusted application from invoking the hardware driver, or
prompt a display of the electronic device with options for user input to authorize invocation of the hardware driver by the first trusted application.

7. The electronic device of claim 1, wherein the hardware driver stored in the normal partition of the non-transitory memory is a copy of the trusted version of the hardware driver.

8. The electronic device of claim 1, wherein the version of the hardware driver is accessible to applications stored in the secure partition of the non-transitory memory and to applications stored in the normal partition of the non-transitory memory associated with the permissive sector.

9. The electronic device of claim 1, wherein the first trusted application invokes at least one of the trusted version of the hardware driver or the version of the hardware driver.

10. The electronic device of claim 1, wherein responsive to the results indicating that the version of the hardware driver stored in the permissive sector does not correspond with the trusted version of the hardware driver, the electronic device:
replaces the hardware driver with the trusted version of the hardware driver,
prevents the first trusted application from invoking the hardware driver, or
configures a display of the electronic device that presents options to receive user input corresponding to authorization that invokes the hardware driver by the first trusted application.

11. The electronic device of claim 1, wherein the second trusted application is further configured to determine whether the trusted version of the hardware driver corresponds with the version of the hardware driver stored in the normal partition of the non-transitory memory in response to powering on the electronic device.

12. The electronic device of claim 1, wherein a non-trusted application in the permissive sector invokes the hardware driver stored in the normal partition without the second trusted application verifying the integrity of the hardware driver.

13. A method for invoking a hardware driver on an electronic device, comprising:
storing, by an electronic device in a secure partition of a non-transitory memory of an electronic device, a trusted version of a hardware driver that provides information about an uncompromised state associated with the hardware driver, wherein the secure partition is associated with a trusted security zone providing a hardware root of trust to the electronic device and an operating system for the secure partition that runs separate from a normal partition operating system;
activating, by at least one processor of the electronic device, a first trusted application stored in the secure partition of the non-transitory memory of the electronic device associated with a trusted security zone providing a hardware root of trust to the electronic device and an operating system for the secure partition that runs separate from a normal partition operating system, wherein the first trusted application is configured to invoke the hardware driver that is initially stored in a normal partition of the non-transitory memory associated with a permissive sector of the electronic device, and wherein the hardware driver is associated with a version;
performing, by a second trusted application stored in the secure partition of the non-transitory memory associated with the trusted security zone and executed by a secure partition of the at least one processor of the electronic device in response to activating the first trusted application, a confidence check on the version of the hardware driver stored in the permissive sector and comparing, by the second trusted application, the trusted version of the hardware driver with the version of the hardware driver stored in the permissive sector and the information about the uncompromised state associated with the hardware driver with a current state of the hardware driver, wherein the permissive sector allows non-trusted applications to invoke hardware drivers stored in the normal partition, and wherein the trusted security zone ceases execution of non-trusted applications in the permissive sector during execution of at least one trusted application in the secure partition;
evaluating, by the second trusted application electronic device, the integrity of the hardware driver based on the confidence check and the comparing; and
enabling, by the second trusted application in response to the evaluation indicating that the version of the hardware driver stored in the permissive sector corresponds with the trusted version of the hardware driver and the current state of the hardware driver corresponds to the uncompromised state associated with the trusted hardware driver, the first trusted application stored and executed in the secure partition of the trusted security zone to invoke the hardware drive, wherein the hardware driver is invoked by the first trusted application responsive to the enablement.

14. The method of claim 13, wherein performing the confidence check comprises performing an error detection action comprising at least one of:
comparing a checksum value of the uncompromised state of the hardware driver with a checksum value of the current state of the hardware driver,
comparing a bit count of the uncompromised state of the hardware driver with a bit count of the current state of the hardware driver,
performing a cyclic redundancy check, performing a repetition code check,
performing a horizontal redundancy check,
performing a vertical redundancy check, checking information about a parity bit,
checking a digital signature, or
comparing a digest of a cryptographic hash function applied to the uncompromised state associated with the hardware driver with a digest of the current state of the hardware driver.

15. The method of claim 13, wherein evaluating the integrity of the hardware driver comprises comparing a result of the confidence check to the uncompromised state of the hardware driver stored in the secure partition of the non-transitory memory associated with the trusted security zone of the electronic device.

16. The method of claim 13, wherein the uncompromised state is associated with being free from sniffers, malware, spyware, Trojans, viruses, and other nefarious programs.

17. The method of claim 13, further comprising:
in response to the result that indicates that the current state of the hardware driver does not correspond to the uncompromised state of the trusted hardware driver,
replacing the hardware driver with the trusted version of hardware driver,
preventing the first trusted application from invoking the hardware driver, or
prompting, by configuration of a display, the user with options.