Patent Publication Number: US-10311246-B1

Title: System and method for secure USIM wireless network access

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 14/947,257, filed on Nov. 20, 2015, entitled “System and Method for Secure USIM Wireless Network Access,” by Lyle W. Paczkowski, et al., which is incorporated herein by reference in its entirety for all purposes. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND 
     Mobile telephones are electronic devices that are used for mobile voice and/or data communications based on wireless network connectivity, which can be provided by base stations known as cell towers or sites. Such electronic devices may authenticate to a cell tower using a wireless communication identifier and/or additional authentication credentials that are stored in a memory module on the electronic device. The memory module may be one of a subscriber identity module (SIM), a universal integrated circuit card (UICC), a universal subscriber identity module (USIM), a removable user identity module (R-UIM), or some other type of memory module. 
     SUMMARY 
     In an embodiment, a user equipment (UE) is disclosed. The UE comprises a radio transceiver, a first non-transitory memory, a first processor, a first operating system, a first clock component, and a memory module, wherein the memory module is one of a subscriber identity module (SIM), a universal integrated circuit card (UICC), a universal subscriber identity module (USIM), or a removable user identity module (R-UIM), wherein clock signals from a second clock component are input to the memory module. The memory module comprises a second non-transitory memory, a second processor, a second operating system, and an application stored in a trusted security zone in the second non-transitory memory, that when executed by the second processor in the trusted security zone, wherein the second operating system accesses the second processor to implement instructions for applications in the second operating system, wherein the trusted security zone provides hardware assisted trust, compares a first mobile equipment identifier (MEID) stored in the first non-transitory memory with a second MEID stored in the memory module. Responsive to the first MEID not matching the second MEID, the application further blocks access of applications outside the memory module to the radio transceiver and periodically examines whether a ping message is received associated with the second MEID from a server in a network of a service provider associated with the UE. Responsive to no such messages being received from the server within a predefined period of time, the application further blocks access of applications outside the memory module to the radio transceiver, wherein counting of the period of time is based on clock signals from the second clock component. 
     In an embodiment, a method of examining whether a user equipment (UE) has been stolen is disclosed. The method comprises periodically transmitting, by an application, a message to a server associated with a lost-and-stolen database to inquire whether the UE is stolen, wherein the application is stored in a trusted security zone in a dedicated non-transitory memory of a subscriber identity module (SIM) on the UE, wherein the SIM comprises a dedicated processor and a dedicated operating system, wherein clock signals from a dedicated clock component are input to the SIM, wherein the trusted security zone provides hardware assisted trust. The method further comprises responsive to a reply from the server indicating that the UE is lost, changing a network access key of the UE, wherein the network access key grants network access to the UE, and responsive to no reply from the server within a predefined period of time, changing the network access key of the UE, wherein the counting of the period of time is based on the clock signals from the dedicated clock component. 
     In an embodiment, a method of parental monitoring by a user equipment (UE) is disclosed. The method comprises monitoring, by a monitor application, activities of applications outside a subscriber identity module (SIM) on the UE, wherein the monitor application is stored in a trusted security zone in a dedicated non-transitory memory of the SIM, wherein the SIM comprises a dedicated processor and a dedicated operating system, wherein clock signals from a dedicated clock component are input to the SIM, and wherein the trusted security zone provides hardware assisted trust. The method further comprises responsive to an input to the UE via an application outside the SIM to connect to a website that is on a blacklist stored on the UE, blocking, by the monitor application, link of the application to a radio transceiver of the UE to access the blacklisted website. 
     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 a communication system according to an embodiment of the disclosure. 
         FIG. 2  is a flow chart illustrating a method according to an embodiment of the disclosure. 
         FIG. 3  is a flow chart illustrating another 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 of a mobile communication device according to an embodiment of the disclosure. 
         FIG. 7  is a block diagram of a computer system according to an embodiment 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. 
     Current memory modules that are used for storing identifying information and authentication credentials on a user equipment (UE) may be vulnerable and lacking potentially beneficial tools for independent operation. A typical example of a memory module may be a removable subscriber identity module (SIM) and the removable SIM may be a smart card. Also, it may only entail moderate efforts for entities with malicious intent to hack or root the memory module. When a memory module is hacked or rooted, the memory module may be taken over and unauthorized access may be made to the memory module. When a user equipment is hacked or rooted, the operating system of the user equipment may be taken over and unauthorized access may be made to the user equipment including the memory module. Thus, reliable implementation of an advanced memory module that suits today&#39;s development of electronic hardware and software technologies and comprises tools for independent operation may be beneficial. For example, an autonomous memory module may be beneficial for its independence characteristics. The present disclosure teaches a system and method for hardware root of trust and trustlet implementation of a memory module on a user equipment. 
     As taught herein, a UE may comprise a first memory, a first processor, a first operating system, a first clock component, and a memory module such as SIM. The SIM may comprise a second memory, a second processor, and a second operating system. In an embodiment, a trusted security zone on the UE may comprise at least part of the second processor and the second memory. The trusted security zone provides hardware assisted trust. To be specific, the trusted security zone provides the UE with a hardware root of trust, a secure execution environment for applications, and secure access to peripherals. In another embodiment, the UE may comprise no trusted security zone. While a SIM is used in the role of memory module in a preferred embodiment, the teachings of the present disclosure may also be extended to other memory modules such as a universal integrated circuit card (UICC), a universal subscriber identity module (USIM), or a removable user identity module (R-UIM). 
     Clock signals from a second clock component may be input to the SIM. The second clock component may be isolated from the first clock component and the first processor. Thus, the first processor may not halt or otherwise tamper with the second clock component. Power may be input to the SIM through a dedicated power line so that as long as the dedicated power line is active, the SIM may be on, regardless of whether the rest of the UE is on. The second memory, the second processor, the trusted security zone, the second operating system, clock signals from the second clock component, and the dedicated power line makes the SIM an autonomous entity, independent from the rest of the UE and thus isolates the SIM from the rest of the UE. This may be helpful when the UE is rooted or hacked. Said in other words, this independence of the SIM decouples it from hacking of the UE. 
     A monitor application may be stored in the trusted security zone and may be executed by the second processor in the trusted security zone. In the case where the UE comprises no trusted security zone, the monitor application may be stored in the memory module and may be executed by the second processor. The monitor application may perform a variety of functions to manage security and/or control related applications of the UE. For example to determine whether or not the UE has been hacked or rooted, the monitor application may compare a first mobile equipment identifier (MEID) stored in the first memory with a second MEID stored in the SIM. The comparison may be performed periodically. When the first MEID does not match the second MEID, the monitor application may determine that the UE has been rooted and may block access of applications outside the SIM to a radio transceiver of the UE, thus blocking voice and data communication. 
     This may especially benefit today&#39;s smart phone leasing business model. In current systems, when a smart phone leased from a wireless communication service provider is hijacked or rooted, the user of the smart phone may stop paying the wireless communication service provider the leasing fee while continuing to use the smart phone. For example, the user may reconfigure the rooted phone for use on a different wireless service provider&#39;s network under their subscription plan, without paying the leasing fee while getting a free phone. The implementation of the monitor application in this disclosure may prevent this from happening or at least prevent the UE from obtaining cellular wireless communication service. A SIM with the current technologies would be compromised when the associated UE is compromised (hijacked or rooted) while a SIM as an autonomous entity implemented with technologies in the present disclosure will not be compromised even when the associated UE is compromised. Thus, the monitor application stored inside the SIM would still detect it when the UE is hijacked or rooted and block access of applications outside the SIM to the radio transceiver of the UE. 
     Additionally, the monitor application may periodically examine whether a ping message is received associated with the second MEID from a server in a network of a communications service provider associated with the UE. When no such messages are received from the server within a predefined period of time, the monitor application may also determine that the UE has been rooted and may block access of applications outside the SIM or outside the trusted security zone to the radio transceiver. Counting of the period of time may be based on clock signals from the second clock component. A monitor application implemented with the current technologies could be tricked to believe that a ping message is received periodically even when the associated UE is compromised (hijacked or rooted) while a monitor application within the SIM as an autonomous entity implemented with technologies in the present disclosure will not be tricked when the associated UE is compromised. Thus, the monitor application stored inside the SIM will detect it when no ping is received, determine that the UE has been rooted, and block access of applications outside the SIM to the radio transceiver of the UE. 
     To determine whether or not the UE is lost or stolen, the monitor application may periodically transmit an inquiry to a lost-and-stolen server associated with a lost-and-stolen database. The lost-and-stolen database may be a national database that stores information related to lost or stolen UEs. For example, a lost UE may be added to a list maintained by the lost-and-stolen database or the lost-and-stolen server when a user of the UE reports that to the lost-and-stolen server. 
     When a reply is received at the UE from the lost-and-stolen server indicating that the UE is lost, the monitor application may change a network access key of the UE. A network access key may be provided by the UE to a network for network access request and/or grant. Each UE may be assigned with a specific network access key by a communications service provider associated with the UE. When the specific network access key is changed, the UE may be denied access to the network. When the rich environment tries to access the network, it may request the SIM to provide credentials such as the network access key to the network. The rich environment may be the operating environment of the UE that is outside the trusted security zone or a trusted execution environment. When no reply is received from the lost-and-stolen server within a predefined period of time, the monitor application may determine that the UE has been stolen or lost and may also change the network access key of the UE. The counting of the period of time may be based on the clock signals from the second clock component. The monitor application within the SIM as an autonomous entity implemented with technologies in the present disclosure will not be compromised even if the UE is compromised. Thus, the monitor application stored inside the SIM will detect when no reply is received, determine that the UE is lost, and change the network access key. 
     The current parental control on a user equipment is typically implemented by an application that is downloaded by a user of the user equipment after the production at the original equipment manufacturer (OEM) and configuration of the UE at the communications service provider retail store. The issue with this type of downloaded applications is that the application usually has very limited control over the user equipment and may be easily compromised itself. Additionally, in the current disclosure, parental control may be realized in an autonomous way on the user equipment. The monitor application may monitor activities of applications outside the SIM on the UE. When an input to the UE via an application outside the SIM is detected by the monitor application to connect to a website that is on a blacklist stored on the UE, the monitor application may block link of the application to the radio transceiver to access the blacklisted website. Such functions may be used not only in parental control, but also in business control or another type of activity control on applications of a UE. The monitor application within the SIM as an autonomous entity implemented with technologies in the present disclosure will not be compromised even if the UE is compromised and thus the monitor application will detect it when an input to the UE via an application outside the SIM to connect to a website that is on a blacklist stored on the UE. Therefore, the monitor application in the present disclosure may really perform parental control or business control. 
     The form of the SIM may not affect the functionality described in this disclosure. In an embodiment, the SIM may be a physical SIM or a virtual SIM. A virtual SIM may be a mobile phone number provided by a wireless communication service provider that does not rely upon a physical SIM to connect phone calls to a UE. For example, the customary services of the physical SIM may be provided by a software application—a virtual SIM—executing at least partly in a trusted security zone. For further details about the virtual SIM, see U.S. Pat. No. 9,161,325, issued Oct. 13, 2015, entitled “Subscriber Identity Module Virtualization,” by Robert E. Urbanek, et al., which is hereby incorporated by reference in its entirety. When the SIM is a physical SIM, it may be a removable SIM such as a separate chip, or an embedded SIM. When the SIM is an embedded SIM, the SIM may be integrated into an application chip or a modem chip on a mother board of the UE. 
     Other applications of the SIM in this disclosure may also be feasible. For example, the SIM may comprise a multi-profile space in the trusted security zone, for example for different communications service providers. A user of the UE may choose from the multiple profiles a profile to use through a trustlet or applet. Each profile may correspond to a subscription account with a specific wireless communication identifier such as a phone number. For example, one identifier may be associated with personal usage and another identifier may be associated with business usage; one identifier may be associated with a first wireless communication service provider and another may be associated with a second wireless communication service provider. The UE may have been provisioned for multiple wireless communication service providers in the case the profiles are associated with more than one wireless communication service provider. The space may further comprise empty space or empty containers to store future profiles. In an embodiment, the SIM may make the process of changing between production and lab keys less difficult. For example, production keys and lab keys may both be securely stored in the trusted security zone on the SIM but may be selected for production and lab scenarios based on predefined rules. Biometric recognition may be implemented with the SIM to identify the correct user of the UE while the biometric information of the user may be stored in the trusted security zone. 
     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. 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. The secure partition may be implemented by a first physical processor, and the normal partition may be implemented by a second physical processor. Alternatively, the secure partition may be implemented by a first virtual processor, and the normal partition may be implemented by a second virtual processor. 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 credentials 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. 
     Turning now to  FIG. 1 , a communication system  100  is described. In an embodiment, the communication system  100  comprises a plurality of user equipments (UEs)  102  and a server  118 . The UE  102  may alternatively be referred to in some contexts as a mobile communication device. The server  118  may be in a network of a communications service provider associated with the UE  102 . The UE  102  may comprise a radio transceiver  104 , a processor  106 , a memory  108 , and a subscriber identity module (SIM)  110 . The SIM  110  may comprise a processor 2   112  and a memory 2   116 . In one embodiment, a trusted security zone  114  on the UE  102  may comprise at least part of the processor 2   112  and the memory 2   116 . The trusted security zone  114  may comprise an application  124 . In another embodiment, the UE  102  may comprise no trusted security zone. 
     The UE  102  may be configured to use a radio transceiver to establish a wireless communication link with an enhanced Node B (eNB)  122 , and the eNB  122  may communicatively couple the UE  102  to a network  120 . The UE  102  may use a network access key to complete an authentication process with the eNB  122  before the eNB  122  will provide a communication link to the UE  102 . The eNB  122  may alternatively be referred to in some contexts as a base transceiver station (BTS) or a cell tower. The server  118  may also be communicatively coupled to the network  120 . The network  120  may comprise any combination of private and public networks. 
     It is understood that the system  100  may comprise any number of UEs  102 , any number of servers  118 , and any number of eNBs  122 . The collectivity of eNBs  122  may be said to comprise a radio access network (RAN), in that these eNBs  122  may provide a radio communication link to the UEs  102  to provide access to the network  120 . The radio transceiver of the UE  102  may communicate with the eNB  122  using any of a variety of wireless communication protocols including a code division multiple access (CDMA) wireless communication protocol, a global system for mobile communication (GSM) wireless communication protocol, a long-term evolution (LTE) wireless communication protocol, a world-wide interoperability for microwave access (WiMAX) wireless communication protocol, or another wireless communication protocol. 
     While a user equipment is used in the role of UE  102  in another embodiment, the teachings of the present disclosure may also be extended to other network/communications capable devices such as a laptop computer, a notebook computer, a tablet computer, a smart phone, a personal digital assistant (PDA), a media player, a headset computer, a wearable computer, a game console, an Internet digital media streaming device, a television, a set top box, a portable storage device, a hotspot, a 2.5 Wi-Fi translator, an Internet of Things (IoT) device, or another network/communications capable device. In an embodiment, the UE  102  may have other components (not shown) such as a near field communication (NFC) radio transceiver, a short range radio transceiver such as a wireless local area network radio transceiver, or other components. 
     The UE  102  may comprise a first operating system, OS 1   130 , and a first clock component, CLK 1   126 . While a SIM  110  is used in the role of a memory module in one embodiment, the teachings of the present disclosure may also be extended to other memory modules such as a universal integrated circuit card (UICC), a universal subscriber identity module (USIM), or a removable user identity module (R-UIM). Clock signals from a second clock component, CLK 2   128 , may be input to the SIM  110 . The CLK 2   128  may be independent of the CLK 1   126  and of the processor  106 . The SIM  110  may comprise a second operating system, OS 2   132 . The independent second clock  128  and second operating system  132  may reduce the opportunity for a rooted UE  102  to be able to compromise the functionality of the SIM  110 . 
     In an embodiment, the SIM  110  may be a physical SIM or a virtual SIM. When the SIM  110  is a physical SIM, it may be a removable SIM such as a separate chip, or an embedded SIM. When the SIM  110  is an embedded SIM, the SIM  110  may be integrated into an application chip or a modem chip on a mother board of the UE  102 . When the SIM  110  is integrated into a modem chip of the UE  102 , the SIM  110  may block access of applications outside the SIM  110  or the trusted security zone  114  to the radio transceiver  104  so that voice calls and data calls made by the applications outside the SIM  110  may be blocked. Power may be input to the SIM  110  through a dedicated power line so that as long as the dedicated power line is active, the SIM  110  is on, regardless of whether the rest of the UE is on. The power is not controlled by the processor  106 . 
     The application  124  stored in the trusted security zone  114  may be executed by the processor 2   112  in the trusted security zone  114 . In the embodiment where the UE  102  comprises no trusted security zone, the application  124  may be stored in the SIM  110  and may be executed by the processor 2   112 . The application  124  may perform a variety of functions to manage security and/or control related applications of the UE  102 . For example, the application  124  may determine periodically whether the UE  102  has been rooted or hacked by unauthorized entities and/or take further action based on the determination. The application  124  may examine periodically whether the UE  102  is stolen or lost and/or take action based on the result of the examination. Additionally, the application  124  may monitor application activities of the UE  102  according to parental control or enterprise control policies stored in the SIM  110 . 
     To determine whether or not the UE  102  is rooted, the application  124  may compare a first equipment identity of the UE  102 , for example a first mobile equipment identifier (MEID), stored in the memory  108  with a second equipment identity of the UE  102 , for example a second MEID, stored in the trusted security zone  114  of the SIM  110 . When the first MEID does not match the second MEID, the UE  102  may be determined to have been rooted. The application  124  may then take action to prevent the UE  102  from being misused or prevent malicious applications to be executed on the UE  102 . For example, the application  124  may block access of applications outside the SIM  110  to the radio transceiver  104  and thus blocks voice calls and data calls made by the applications outside the SIM  110 . 
     This function may be useful when a UE  102  leased from a wireless communication service provider is hijacked or rooted by a user of the UE  102  wishing to continue using the leased UE  102  without having to pay a leasing fee. The user of the UE  102  may have to bring in the UE  102  and pay the balance of a service bill to have communication ability of the UE  102  restored after the UE is determined to have been rooted and thus blocked from radio transceiver  104  access, hence is unable to make voice or data calls. The SIM  110  as an autonomous entity implemented with technologies in the present disclosure will not be compromised even when the UE  102  is compromised. Thus, the application  124  stored inside the SIM  110  would still detect it when the UE  102  is hijacked or rooted and block access of applications outside the SIM  110  to the radio transceiver  104  of the UE  102 . 
     Alternatively or additionally, the application  124  may periodically examine whether or not a ping message associated with the second MEID is received from the server  118 . When no such messages are received from the server  118  within a predefined period of time, the application  124  may determine that the UE  102  has been rooted. Counting of the period of time may be based on clock signals from the CLK 2   128 . Without the CLK 2   128 , when the UE  102  is rooted by an unauthorized entity, the CLK 1   126  may also be halted, altered, or manipulated in another way by the unauthorized entity. Since the CLK 2   128  is independent of the CLK 1   126  and of the processor  106 , even if the UE  102  is rooted and the processor  106  is taken over by an unauthorized entity, the CLK 2   128  will not be manipulated by the unauthorized entity. The application  124  may then take action to prevent the UE  102  from being misused. For example, the application  124  may block access of applications outside the SIM  110  to the radio transceiver  104  and/or change the first MEID stored in the memory  108  so that the first MEID would not match the second MEID. 
     To determine whether or not the UE  102  is stolen or lost, the application  124  may periodically transmit a message or an inquiry to a lost-and-stolen server (not shown) associated with a lost-and-stolen database. The lost-and-stolen database may be a national database that stores information of lost or stolen UEs  102 . For example, when a UE is lost, a user of the UE may register online to indicate that the UE is lost. That information may be stored in the national lost-and-stolen database. 
     When a reply is received at the UE  102  from the lost-and-stolen server indicating that the UE  102  is lost, the application  124  may change a network access key of the UE  102 . In an embodiment, the network access key may be provided by the UE  102  to a network for network access request and/or grant. On the other hand, when no reply is received from the lost-and-stolen server within a predefined period of time, the application  124  may also change the network access key of the UE  102 . The counting of the period of time may be based on the clock signals from the CLK 2   128 . 
     The message may be transmitted to the lost-and-stolen server periodically using a dedicated trusted communication channel or a dedicated secure communication channel via the radio transceiver  104  of the UE  102 . Trusted computation and/or trusted communication is based on the hardware assisted security that reduces the ability of nefarious software or corrupt devices to write, read, or otherwise access trusted memory, trusted processing, or trusted messages. The SIM  110  or the trusted security zone  114  has an independent path to the radio transceiver  104  and this independent path may not be blocked by the processor  106 . For example, access of applications stored outside the trusted security zone  114  to the radio transceiver  104  may be blocked by the application  124  while the message is being transmitted by the radio transceiver  104 . The dedicated secure communication channel may utilize a dedicated communication protocol stack. 
     Additionally, the application  124  may monitor activities of applications outside the SIM  110  or outside the trusted security zone  114  on the UE  102 , for example for parental control or business control purposes. Parental control or business control policies may be stored in the trusted security zone  114 . For example, a parental control policy may prohibit texting in restricted time periods. In case of an input to the UE  102  via an application outside the SIM  110  or the trusted security zone  114  to connect to a website that is on a blacklist stored on the UE  102 , the application  124  may block link of the application to the radio transceiver  104  to access the blacklisted website. 
     Turning now to  FIG. 2 , a method  200  is described. At block  202 , a message is periodically transmitted by an application to a server associated with a lost-and-stolen database to inquire whether the UE is stolen, wherein the application is stored in a trusted security zone in a dedicated non-transitory memory of a subscriber identity module (SIM) on the UE, wherein the SIM comprises a dedicated processor and a dedicated operating system, wherein clock signals from a dedicated clock component are input to the SIM, wherein the trusted security zone provides hardware assisted trust. For example, a message may be transmitted periodically by the application  124  to a lost-and-stolen server associated with a national lost-and-stolen database to inquire whether or not the UE  102  is stolen or lost. 
     At block  204 , responsive to a reply from the server indicating that the UE  102  is lost, a network access key of the UE  102  is changed, wherein the network access key is used by the UE  102  to complete an authentication process with the eNB  122  before the eNB  122  will provide a communication link to the UE  102 . At block  206 , Responsive to no reply from the server within a predefined period of time, the network access key of the UE  102  is changed, wherein the counting of the period of time is based on the clock signals from the dedicated clock component. When the network access key is changed, the UE  102  cannot make voice calls or data calls and the user of the UE  102  must bring the UE  102  in to a retail store or service center to have the issue resolved. If the leasing agreement has been violated in some way the UE  102  may be confiscated or the user may need to pay delinquent leasing fees and a service fee for restoration of service to the UE  102 . 
     Turning now to  FIG. 3 , a method  300  is described. At block  302 , activities of applications outside a subscriber identity module (SIM)  110  on the UE  102  are monitored by a monitor application  124 , wherein the monitor application  124  is stored in a trusted security zone  114  in a dedicated non-transitory memory  116  of the SIM  110 , wherein the SIM  110  comprises a dedicated processor 2   112  and a dedicated operating system, wherein clock signals from a dedicated clock component are input to the SIM  110 , and wherein the trusted security zone  114  provides hardware assisted trust. At block  304 , responsive to an input to the UE  102  via an application outside the SIM  110  to connect to a website that is on a blacklist stored on the UE  102 , block, by the monitor application  124 , link of the application to a radio transceiver  104  of the UE  102  to access the blacklisted website. 
       FIG. 4  depicts the user equipment (UE)  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 UE  400  may take various forms including a wireless handset, a pager, a personal digital assistant (PDA), a gaming device, or a media player. The UE  400  includes a touchscreen display  402  having a touch-sensitive surface for input by a user. A small number of application icons  404  are illustrated within the touch screen display  402 . It is understood that in different embodiments, any number of application icons  404  may be presented in the touch screen display  402 . In some embodiments of the UE  400 , a user may be able to download and install additional applications on the UE  400 , and an icon associated with such downloaded and installed applications may be added to the touch screen display  402  or to an alternative screen. The UE  400  may have other components such as electro-mechanical switches, speakers, camera lenses, microphones, input and/or output connectors, and other components as are well known in the art. The UE  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 UE  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 UE  400  may further execute one or more software or firmware applications in response to user commands. These applications may configure the UE  400  to perform various customized functions in response to user interaction. Additionally, the UE  400  may be programmed and/or configured over-the-air, for example from a wireless base station, a wireless access point, or a peer UE  400 . The UE  400  may execute a web browser application which enables the touch screen 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 UE  400  or any other wireless communication network or system. 
       FIG. 5  shows a block diagram of the UE  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 UE  400 . The UE  400  includes a digital signal processor (DSP)  502  and a memory  504 . As shown, the UE  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 , one or more electro-mechanical switches  528 , a touch screen liquid crystal display (LCD) with a touch screen display  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 UE  400  may include another kind of display that does not provide a touch sensitive screen. In an embodiment, the UE  400  may include both the touch screen display  530  and additional display component 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 UE  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 UE  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 UE  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 UE  400  to communicate wirelessly with other nearby handsets and/or wireless base stations. In an embodiment, the UE  400  may comprise a near field communication (NFC) transceiver. The NFC transceiver may be used to complete payment transactions with point-of-sale terminals or other communications exchanges. In an embodiment, the UE  400  may comprise a radio frequency identify (RFID) reader and/or writer device. 
     The switches  528  may couple to the DSP  502  via the input/output interface  518  to provide one mechanism for the user to provide input to the UE  400 . Alternatively, one or more of the switches  528  may be coupled to a motherboard of the UE  400  and/or to components of the UE  400  via a different path (e.g., not via the input/output interface  518 ), for example coupled to a power control circuit (power button) of the UE  400 . The touch screen display  530  is another input mechanism, which further displays text and/or graphics to the user. The touch screen LCD controller  532  couples the DSP  502  to the touch screen display  530 . The GPS receiver  538  is coupled to the DSP  502  to decode global positioning system signals, thereby enabling the UE  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 UE  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 UE  400  to browse content and/or the Internet, for example when the UE  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 UE  400  to play audio or audiovisual media. The JAVA applets  612  may be executed by the UE  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 kernel (OS kernel)  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. 
     Additionally, after the system  380  is turned on or booted, the CPU  382  may execute a computer program or application. For example, the CPU  382  may execute software or firmware stored in the ROM  386  or stored in the RAM  388 . In some cases, on boot and/or when the application is initiated, the CPU  382  may copy the application or portions of the application from the secondary storage  384  to the RAM  388  or to memory space within the CPU  382  itself, and the CPU  382  may then execute instructions that the application is comprised of. In some cases, the CPU  382  may copy the application or portions of the application from memory accessed via the network connectivity devices  392  or via the I/O devices  390  to the RAM  388  or to memory space within the CPU  382 , and the CPU  382  may then execute instructions that the application is comprised of. During execution, an application may load instructions into the CPU  382 , for example load some of the instructions of the application into a cache of the CPU  382 . In some contexts, an application that is executed may be said to configure the CPU  382  to do something, e.g., to configure the CPU  382  to perform the function or functions promoted by the subject application. When the CPU  382  is configured in this way by the application, the CPU  382  becomes a specific purpose computer or a specific purpose machine. 
     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 that promote radio communications using protocols such as code division multiple access (CDMA), global system for mobile communications (GSM), long-term evolution (LTE), worldwide interoperability for microwave access (WiMAX), near field communications (NFC), radio frequency identity (RFID), 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 ), flash drive, 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 system  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.