WO2018058556A1

WO2018058556A1 - Technology to provide secure key protection and flexible file sharing in encrypted file system

Info

Publication number: WO2018058556A1
Application number: PCT/CN2016/101147
Authority: WO
Inventors: Weigang Li; Ned M. Smith; Changzheng WEI; Wenqian YU; Junyuan Wang
Original assignee: Intel Corporation
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-05
Also published as: DE112016007290T5

Abstract

Systems, apparatuses and methods may provide for technology that conducts, based on signed class information from a user, a membership verification of the user with respect to a file class. Additionally, if the membership verification is successful, a key encryption key may be generated based on the signed class information and a root key embedded in a trusted environment. A file encryption key may also be generated based on the key encryption key and context information associated with a digital file in the file class.

Description

[Title established by the ISA under Rule 37.2] TECHNOLOGY TO PROVIDE SECURE KEY PROTECTION AND FLEXIBLE FILE SHARING IN ENCRYPTED FILE SYSTEM

TECHNICAL FIELD

Embodiments generally relate to data security. More particularly, embodiments relate to technology that provides secure key protection and flexible file sharing in encrypted file systems.

BACKGROUND

Encrypted file systems may facilitate the sharing of sensitive data among multiple users. Conventional file access control mechanisms, however, may rely on the operating system (OS) to manage complex policies relating users, groups and files to one another. Accordingly, when lifecycle changes of all objects in the system are made, conventional solutions may encounter a central bottleneck. Moreover, conventional file access control mechanisms may focus on protecting file encryption keys after encryption. In such cases, the file encryption key may be used in plaintext that is not protected in memory during encryption. As a result, potential security vulnerabilities such as cold boot attacks may become a concern.

BRIEF DESCRIPTION OF THE DRAWINGS

The various advantages of the embodiments will become apparent to one skilled in the art by reading the following specification and appended claims, and by referencing the following drawings, in which:

FIG. 1 is a block diagram of an example of a computing system according to an embodiment；

FIG. 2 is a block diagram of an example of a classification and authentication subsystem according to an embodiment；

FIG. 3 is a block diagram of an example of a method of operating a trusted environment apparatus according to an embodiment；

FIG. 4 is a block diagram of an example of a trusted environment apparatus according to an embodiment；

FIG. 5 is an illustration of an example of a file access and file class initialization according to an embodiment；

FIG. 6 is an illustration of an example of a file encryption sequence according to an embodiment； and

FIG. 7 is an illustration of an example of a file decryption sequence according to an embodiment.

FIG. 8 is a block diagram of an example of a processor according to an embodiment； and

FIG. 9 is a block diagram of an example of a computing system according to an embodiment.

DESCRIPTION OF EMBODIMENTS

Turning now to FIG. 1, a computing system 10 (e.g., server, desktop computer, notebook computer, tablet computer, convertible tablet, smart phone, personal digital assistant/PDA, media player, wearable device, etc. ) is shown in which one or more digital files 12 (12a, 12b) may be shared among two or more users (e.g., “User A” , “User B” ) . A classification and authentication subsystem 14 may generally classify the digital files 12 and initially authenticate the users. More particularly, the subsystem 14 may assign the files 12 to various file classes, wherein the file classes may correspond to, for example, to particular authentication groups (e.g., Unclassified, Classified, Official, Secret, Top Secret, Scientific, Military, Energy, etc. ) . The classification and authentication subsystem 14 may also conduct initial authentications of the users and provide the users with credentials and class information, wherein the credentials and class information enable the users to securely store the files 12 to a file subsystem 16 and retrieve the files 12 from the file subsystem 16. One or more user interface (UI) devices 18 (e.g., displays, touch screens, speakers, microphones, mice, touch pads, keyboards) may facilitate the entry of authentication information by the users as well as the presentation (e.g., visual and/or audible) of information regarding the files 12 to the users. In the illustrated example, the computing system 10 also includes an operating system (OS) 20 and a trusted environment apparatus 22 (e.g., hierarchical storage module/HSM, trusted execution environment/TEE) that is separate from the OS 20.

As will be discussed in greater detail, the trusted environment apparatus 22 may enable secure key protection and flexible file sharing in an encrypted fashion. In this regard, the illustrated trusted environment apparatus 22 includes a file access authenticator 24, a plurality of hierarchical key derivers 26, a file encryption service 28 and a root key 30 (e.g., enhanced privacy identifier/EPID key) . The authenticator 24 may conduct, based on signed class information from a user such as, for example, User A, a membership verification of the user with respect to a file class (e.g., File Class 1) . Additionally, the hierarchical key derivers 26 may include a first key deriver (not shown, e.g., first key derivation function/KDF) communicatively coupled to the authenticator 24, wherein the first key deriver generates, if the membership verification function is successful, a key encryption key (e.g., Class 1 key) based on the signed class information and the root key 30. The hierarchical key derivers 26 may also include a second key deriver (not shown, e.g., second KDF) communicatively coupled to the first key deriver, wherein the second key deriver generates a file encryption key based on the key encryption key and context information associated with one or more of the digital files 12. The hierarchical nature of the key derivers 26 combined with the location of the key derivers 26 and the root key 30 within the trusted environment apparatus 22 may substantially enhance the security of the system 10.

FIG. 2 shows an example of the classification and authentication subsystem 14 in which a first file class 32 (e.g., “File Class 1” ) is associated with a first public key (e.g., “EPID PubKey1” ) and a second file class 34 (e.g., “File Class 2” ) is associated with a second public key (e.g., “EPID PubKey2” ) . The first file class 32, which includes a first set of digital files ( “File 1” through “File n” ) , might correspond to a particular authentication group (e.g., Unclassified) . Similarly, the second file class 34, which includes a second set of digital files ( “File a” through “File z” ) , may correspond to another authentication group (e.g., Classified) . In the illustrated example, a first user 36 ( “User A” ) has been granted access to the first file class 32. Accordingly, the first user 36 may be provisioned with credentials including a public key ( “PubK1” ) associated with the first file class 32 and a private key ( “Privkey1A” ) associated with the first file class 32 and the first user 36. When reading or writing files such as, for example, File 1, to storage, the first user 36 may use the credentials to assert membership in the first file class 32 and enable secure storage/retrieval of the file.

By contrast, a second user 38 ( “User B” ) may have been granted access to both the first file class 32 and the second file class 34. Accordingly, the second user 38 may be provisioned with credentials including the public key associated with the first file class 32, a private key ( “Privkey1B” ) associated with the first file class 32 and the second user 38, a public key ( “PubK2” ) associated with the second file class 34 and a private key ( “Privkey2B” ) associated with the second file class 34 and the second user 38. The second user 38 may therefore use the credentials to assert membership in the second file class 34 when reading or writing files such as, for example, File a, as well as to assert membership in the first file class 32 when reading or writing files such as, for example, File 2. Moreover, a third user 40 ( “User C” ) might have been granted access to both the first file class 32 and the second file class 34, a fourth user 42 ( “User D” ) may have been granted access only to the second file class 34, and so forth.

FIG. 3 shows a method 44 of operating a trusted environment apparatus. The method 44 may generally be implemented in a security-enhanced computing system such as, for example, the system 10 (FIG. 1) , already discussed. More particularly, the method 44 may be implemented as one or more modules in a set of logic instructions stored in a non-transitory machine-or computer-readable storage medium such as random access memory (RAM) , read only memory (ROM) , programmable ROM (PROM) , firmware, flash memory, etc., in configurable logic such as, for example, programmable logic arrays (PLAs) , field programmable gate arrays (FPGAs) , complex programmable logic devices (CPLDs) , in fixed-functionality hardware logic using circuit technology such as, for example, application specific integrated circuit (ASIC) , complementary metal oxide semiconductor (CMOS) or transistor-transistor logic (TTL) technology, or any combination thereof.

For example, computer program code to carry out operations shown in the method 44 may be written in any combination of one or more programming languages, including an object oriented programming language such as JAVA, SMALLTALK, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. Additionally, logic instructions might include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, state-setting data, configuration data for integrated circuitry, state information that personalizes electronic circuitry and/or other structural components that are native to hardware (e.g., host processor, central processing unit/CPU, microcontroller, etc. ) .

Illustrated processing block 46 provides for conducting, based on signed class information from a user, a membership verification of the user with respect to a file class. The signed class information may include, for example, a public key associated with the file class and a private key signature associated with the file class and the user. A determination may be made at block 48 as to whether the membership verification was successful (e.g., valid private key signature) . If so, block 50 may generate a key encryption key based on the signed class information and a root key embedded in a trusted environment. Additionally, a file encryption key may be generated at block 52 based on the key encryption key and context information associated with a digital file. In one example, the context information includes a hash of the digital file, although other context information such as, for example, geolocation information, timestamps, etc., may be used. Block 52 may also provide for using the file encryption key to encrypt the digital file and writing the encrypted digital file and the context information to storage (e.g., in a file storage situation) . In another example, block 52 may include reading the digital file and the context information from storage and using the file encryption key to decrypt the digital file (e.g., in a file retrieval situation) . If it is determined at block 48 that the membership verification was unsuccessful (e.g., invalid private key signature) , block 56 may deny read and/or write access with respect to the digital file.

FIG. 4 shows the trusted environment apparatus 22 in an example in which a first key deriver 60 (e.g., KDF) generates a key encryption key 64 ( “ClassKey” ) within the trusted environment apparatus 22 based on class information 62 and the root key 30 ( “RootKey” ) . Additionally, a second key deriver 66 may generate a file encryption key 68 ( “File1Key” ) based on the key encryption key 64 and context information 70 (e.g., “File Hash” ) associated with a digital file (e.g., “File 1” ) . The trusted environment apparatus 22 may include logic instructions, configurable logic, fixed-functionality hardware logic, etc., or any combination thereof.

Turning now to FIG. 5, a file access and file classification initialization is shown. In the illustrated example, an EPID issuer 72 provides a first user 74 ( “User A” ) with access to a first file class ( “Class 1” ) and a third file class “ (Class 3” ) . More particularly, the EPID issuer 72 provisions the first user 74 with a public key ( “gpk1” ) associated with the first file class, a private key ( “sk1A” ) associated with the first file class and the first user 74, a public key ( “gpk3” ) associated with the third file class, and a private key ( “sk3A” ) associated with the third file class and the first user 74. Similarly, the EPID issuer 72 may provide a second user 76 ( “User B” ) with access to the first file class by provisioning the second user 76 with the public key associated with the first file class and a private key ( “sk1B” ) associated with the first file class and the second user 76. The illustrated solution therefore enables the use of EPID join and revoke protocols.

FIG. 6 shows a file encryption sequence in which a trusted environment apparatus 80 enables the secure storage of a digital file 82. In general, the trusted environment 80 may be incorporated into a computing system operated by a particular user (e.g., “User A” ) . The illustrated trusted environment apparatus 80, which may be readily substituted for the apparatus 22 (FIGs. 1 and 4) , already discussed, includes an authenticator 84 to conduct a membership verification of the user with respect to a file class based on signed class information 81 from the user. Additionally, the trusted environment apparatus 80 may include a plurality of hierarchical key derivers 86 (86a, 86b) .

For example, a first key deriver 86a may be communicatively coupled to the authenticator 84, wherein the first key deriver 86a is configured to generate, if the membership verification is successful, a key encryption key 88 based on the signed class information 81 and a root key 90 that is embedded in the trusted environment apparatus 80. A second key deriver 86b may be communicatively coupled to the first key deriver 86a. In the illustrated example, the second key deriver 86b generates a file encryption key 92 based on the key encryption key 88 and context information 94 associated with the digital file 82. An encryptor 96 (e.g., encryption service) may therefore use the file encryption key 92 to encrypt the digital file 82, wherein a storage interface 98 may write the encrypted digital file 99 and the context information 94 to storage. The signed class information 81 may also be stored with the encrypted digital file 99. If the membership verification is unsuccessful, the illustrated authenticator 84 terminates the storage procedure.

FIG. 7 shows a file decryption sequence in which a trusted environment apparatus 100 enables the secure retrieval of the encrypted digital file 99. In general, the trusted environment 1000 may be incorporated into a computing system operated by a particular user (e.g., “User B” ) . The illustrated apparatus 100, which may be readily substituted for the apparatus 22 (FIGs. 1 and 4) , already discussed, includes an authenticator 102 to conduct a membership verification of the user with respect to the file class based on signed class information 83 from the user. Additionally, the trusted environment apparatus 100 may include a plurality of hierarchical key derivers 104 (104a, 104b) .

For example, a first key deriver 104a may be communicatively coupled to the authenticator 102, wherein the first key deriver 104a is configured to generate, if the membership verification is successful, a key encryption key 106 based on the signed class information 83 and the root key 90 that is also embedded in the trusted environment apparatus 100. In this regard, the root key 90 may be distributed and/or shared across multiple computing systems. A second key deriver 104b may be communicatively coupled to the first key deriver 104a. In the illustrated example, the second key deriver 104b generates a file encryption key 110 based on the key encryption key 106 and the context information 94 associated with the digital file 82. A storage interface 114 may read the encrypted digital file 99 and the context information 94 from storage, wherein a decryptor 112 (e.g., encryption service) may use the file encryption key 110 to decrypt the digital file.

FIG. 8 illustrates a processor core 200 according to one embodiment. The processor core 200 may be the core for any type of processor, such as a micro-processor, an embedded processor, a digital signal processor (DSP) , a network processor, or other device to execute code. Although only one processor core 200 is illustrated in FIG. 8, a processing element may alternatively include more than one of the processor core 200 illustrated in FIG. 8. The processor core 200 may be a single-threaded core or, for at least one embodiment, the processor core 200 may be multithreaded in that it may include more than one hardware thread context (or “logical processor” ) per core.

FIG. 8 also illustrates a memory 270 coupled to the processor core 200. The memory 270 may be any of a wide variety of memories (including various layers of memory hierarchy) as are known or otherwise available to those of skill in the art. The memory 270 may include one or more code 213 instruction (s) to be executed by the processor core 200, wherein the code 213 may implement one or more aspects of the method 44 (FIG. 3) , already discussed. The processor core 200 follows a program sequence of instructions indicated by the code 213. Each instruction may enter a front end portion 210 and be processed by one or more decoders 220. The decoder 220 may generate as its output a micro operation such as a fixed width micro operation in a predefined format, or may generate other instructions, microinstructions, or control signals which reflect the original code instruction. The illustrated front end portion 210 also includes register renaming logic 225 and scheduling logic 230, which generally allocate resources and queue the operation corresponding to the convert instruction for execution.

The processor core 200 is shown including execution logic 250 having a set of execution units 255-1 through 255-N. Some embodiments may include a number of execution units dedicated to specific functions or sets of functions. Other embodiments may include only one execution unit or one execution unit that can perform a particular function. The illustrated execution logic 250 performs the operations specified by code instructions.

After completion of execution of the operations specified by the code instructions, back end logic 260 retires the instructions of the code 213. In one embodiment, the processor core 200 allows out of order execution but requires in order retirement of instructions. Retirement logic 265 may take a variety of forms as known to those of skill in the art (e.g., re-order buffers or the like) . In this manner, the processor core 200 is transformed during execution of the code 213, at least in terms of the output generated by the decoder, the hardware registers and tables utilized by the register renaming logic 225, and any registers (not shown) modified by the execution logic 250.

Although not illustrated in FIG. 8, a processing element may include other elements on chip with the processor core 200. For example, a processing element may include memory control logic along with the processor core 200. The processing element may include I/O control logic and/or may include I/O control logic integrated with memory control logic. The processing element may also include one or more caches.

Referring now to FIG. 9, shown is a block diagram of a computing system 1000 embodiment in accordance with an embodiment. Shown in FIG. 9 is a multiprocessor system 1000 that includes a first processing element 1070 and a second processing element 1080. While two

processing elements

1070 and 1080 are shown, it is to be understood that an embodiment of the system 1000 may also include only one such processing element.

The system 1000 is illustrated as a point-to-point interconnect system, wherein the first processing element 1070 and the second processing element 1080 are coupled via a point-to-point interconnect 1050. It should be understood that any or all of the interconnects illustrated in FIG. 9 may be implemented as a multi-drop bus rather than point-to-point interconnect.

As shown in FIG. 9, each of

processing elements

1070 and 1080 may be multicore processors, including first and second processor cores (i.e.,

processor cores

1074a and 1074b and

processor cores

1084a and 1084b) .

Such cores

1074a, 1074b, 1084a, 1084b may be configured to execute instruction code in a manner similar to that discussed above in connection with FIG. 8.

Each

processing element

1070, 1080 may include at least one shared

cache

1896a, 1896b. The shared

cache

1896a, 1896b may store data (e.g., instructions) that are utilized by one or more components of the processor, such as the

cores

1074a, 1074b and 1084a, 1084b, respectively. For example, the shared

cache

1896a, 1896b may locally cache data stored in a

memory

1032, 1034 for faster access by components of the processor. In one or more embodiments, the shared

cache

1896a, 1896b may include one or more mid-level caches, such as level 2 (L2) , level 3 (L3) , level 4 (L4) , or other levels of cache, a last level cache (LLC) , and/or combinations thereof.

While shown with only two

processing elements

1070, 1080, it is to be understood that the scope of the embodiments are not so limited. In other embodiments, one or more additional processing elements may be present in a given processor. Alternatively, one or more of

processing elements

1070, 1080 may be an element other than a processor, such as an accelerator or a field programmable gate array. For example, additional processing element (s) may include additional processors (s) that are the same as a first processor 1070, additional processor (s) that are heterogeneous or asymmetric to processor a first processor 1070, accelerators (such as, e.g., graphics accelerators or digital signal processing (DSP) units) , field programmable gate arrays, or any other processing element. There can be a variety of differences between the

processing elements

1070, 1080 in terms of a spectrum of metrics of merit including architectural, micro architectural, thermal, power consumption characteristics, and the like. These differences may effectively manifest themselves as asymmetry and heterogeneity amongst the

processing elements

1070, 1080. For at least one embodiment, the

various processing elements

1070, 1080 may reside in the same die package.

The first processing element 1070 may further include memory controller logic (MC) 1072 and point-to-point (P-P) interfaces 1076 and 1078. Similarly, the second processing element 1080 may include a MC 1082 and

P-P interfaces

1086 and 1088. As shown in FIG. 9, MC’s 1072 and 1082 couple the processors to respective memories, namely a memory 1032 and a memory 1034, which may be portions of main memory locally attached to the respective processors. While the

MC

1072 and 1082 is illustrated as integrated into the

processing elements

1070, 1080, for alternative embodiments the MC logic may be discrete logic outside the

processing elements

1070, 1080 rather than integrated therein.

The first processing element 1070 and the second processing element 1080 may be coupled to an I/O subsystem 1090 via P-P interconnects 1076 1086, respectively. As shown in FIG. 9, the I/O subsystem 1090 includes

P-P interfaces

1094 and 1098. Furthermore, I/O subsystem 1090 includes an interface 1092 to couple I/O subsystem 1090 with a high performance graphics engine 1038. In one embodiment, bus 1049 may be used to couple the graphics engine 1038 to the I/O subsystem 1090. Alternately, a point-to-point interconnect may couple these components.

In turn, I/O subsystem 1090 may be coupled to a first bus 1016 via an interface 1096. In one embodiment, the first bus 1016 may be a Peripheral Component Interconnect (PCI) bus, or a bus such as a PCI Express bus or another third generation I/O interconnect bus, although the scope of the embodiments are not so limited.

As shown in FIG. 9, various I/O devices 1014 (e.g., speakers, cameras, sensors) may be coupled to the first bus 1016, along with a bus bridge 1018 which may couple the first bus 1016 to a second bus 1020. In one embodiment, the second bus 1020 may be a low pin count (LPC) bus. Various devices may be coupled to the second bus 1020 including, for example, a keyboard/mouse 1012, communication device (s) 1026, and a data storage unit 1019 such as a disk drive or other mass storage device which may include code 1030, in one embodiment. The illustrated code 1030, which may be similar to the code 213 (FIG. 8) , may implement the method 44 (FIG. 3) , already discussed. Further, an audio I/O 1024 may be coupled to second bus 1020 and a battery port 1010 may supply power to the computing system 1000.

Note that other embodiments are contemplated. For example, instead of the point-to-point architecture of FIG. 9, a system may implement a multi-drop bus or another such communication topology. Also, the elements of FIG. 9 may alternatively be partitioned using more or fewer integrated chips than shown in FIG. 9.

Additional Notes and Examples:

Example 1 may include a security-enhanced computing system comprising a display to visually present information regarding a digital file, a file subsystem including storage, and a trusted environment apparatus communicatively coupled to the file subsystem, the trusted environment apparatus including a root key embedded in the trusted environment apparatus, an authenticator to conduct, based on signed class information from a user, a membership verification of the user with respect to a file class, a first key deriver communicatively coupled to the authenticator, the first key deriver to generate, if the membership verification is successful, a key encryption key based on the signed class information and the root key, and a second key deriver communicatively coupled to the first key deriver, the second key deriver to generate a file encryption key based on the key encryption key and context information associated with the digital file.

Example 2 may include the system of Example 1, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.

Example 3 may include the system of Example 1, wherein the file class is to correspond to a particular authentication group.

Example 4 may include the system of Example 1, wherein the context information is to include a hash of the digital file.

Example 5 may include the system of any one of Examples 1 to 4, wherein the trusted environment apparatus further includes an encryptor to use the file encryption key to encrypt the digital file, and a storage interface to write the encrypted digital file and the context information to the storage.

Example 6 may include the system of any one of Examples 1 to 4, wherein the trusted environment apparatus further includes an encryptor to use the file encryption key to encrypt the digital file, and a storage interface to write the encrypted digital file and the context information to the storage.

Example 7 may include a trusted environment apparatus comprising a root key embedded in the trusted environment, an authenticator to conduct, based on signed class information from a user, a membership verification of the user with respect to a file class, a first key deriver communicatively coupled the authenticators, the first key deriver to generate, if the membership verification is successful, a key encryption key based on the signed class information and the root key, and a second key deriver communicatively coupled to the first key deriver, the second key deriver to generate a file encryption key based on the key encryption key and context information associated with a digital file.

Example 8 may include the apparatus of Example 7, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.

Example 9 may include the apparatus of Example 7, wherein the file class is to correspond to a particular authentication group.

Example 10 may include the apparatus of Example 7, wherein the context information is to include a hash of the digital file.

Example 11 may include the apparatus of any one of Examples 7 to 10, further including an encryptor to use the file encryption key to encrypt the digital file, and a storage interface to write the encrypted digital file and the context information to storage.

Example 12 may include the apparatus of any one of Examples 7 to 10, further including a storage interface to read the digital file and the context information from storage, and a decryptor to use the file encryption key to decrypt the digital file.

Example 13 may include a method of operating a trusted environment apparatus comprising conducting, based on signed class information from a user, a membership verification of the user with respect to a file class, generating, if the membership verification is successful, a key encryption key based on the signed class information and a root key embedded in a trusted environment, and generating a file encryption key based on the key encryption key and context information associated with a digital file.

Example 14 may include the method of Example 13, wherein the signed class information includes a public key associated with the file class and a private key signature associated with the file class and the user.

Example 15 may include the method of Example 13, wherein the file class corresponds to a particular authentication group.

Example 16 may include the method of Example 13, wherein the context information includes a hash of the digital file.

Example 17 may include the method of any one of Examples 13 to 16, further including using the file encryption key to encrypt the digital file, and writing the encrypted digital file and the context information to storage.

Example 18 may include the method of any one of Examples 13 to 16, further including reading the digital file and the context information from storage, and using the file encryption key to decrypt the digital file.

Example 19 may include at least one computer readable storage medium comprising a set of instructions, which when executed by a computing device, cause the computing device to conduct, based on signed class information from a user, a membership verification of the user with respect to a file class, generate, if the membership verification is successful, a key encryption key based on the signed class information and a root key embedded in a trusted environment, and generate a file encryption key based on the key encryption key and context information associated with a digital file.

Example 20 may include the at least one computer readable storage medium of Example 19, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.

Example 21 may include the at least one computer readable storage medium of Example 19, wherein the file class is to correspond to a particular authentication group.

Example 22 may include the at least one computer readable storage medium of Example 19, wherein the context information is to include a hash of the digital file.

Example 23 may include the at least one computer readable storage medium of any one of Examples 19 to 22, wherein the instructions, when executed, cause the computing device to use the file encryption key to encrypt the digital file, and write the encrypted digital file and the context information to storage.

Example 24 may include the at least one computer readable storage medium of any one of Examples 19 to 22, wherein the instructions, when executed, cause the computing device to read the digital file and the context information from storage, and use the file encryption key to decrypt the digital file.

Example 25 may include a trusted environment apparatus comprising means for conducting, based on signed class information from a user, a membership verification of the user with respect to a file class, means for generating, if the membership verification is successful, a key encryption key based on the signed class information and a root key embedded in a trusted environment, and means for generating a file encryption key based on the key encryption key and context information associated with a digital file.

Example 26 may include the apparatus of Example 25, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.

Example 27 may include the apparatus of Example 25, wherein the file class is to correspond to a particular authentication group.

Example 28 may include the apparatus of Example 25, wherein the context information is to include a hash of the digital file.

Example 29 may include the apparatus of any one of Examples 25 to 28, further including means for using the file encryption key to encrypt the digital file, and means for writing the encrypted digital file and the context information to storage.

Example 30 may include the apparatus of any one of Examples 25 to 28, further including means for reading the digital file and the context information from storage, and means for using the file encryption key to decrypt the digital file.

Thus, technology described herein may introduce an innovative file access control and encryption solution based on EPID technology and HSM. Accordingly, secure key and encryption operations may be maintained within a trusted area. The technology described herein may therefore render computing systems less susceptible to cold boot attacks because the keys remain in a secure location even when power is not applied to the system. Moreover, although a central authority may define group rights for consistency across an organization/community, the definition of the group may be relatively straightforward. Accordingly, lifecycle changes of all objects in the system may not lead to a bottleneck.

Embodiments are applicable for use with all types of semiconductor integrated circuit ( “IC” ) chips. Examples of these IC chips include but are not limited to processors, controllers, chipset components, programmable logic arrays (PLAs) , memory chips, network chips, systems on chip (SoCs) , SSD/NAND controller ASICs, and the like. In addition, in some of the drawings, signal conductor lines are represented with lines. Some may be different, to indicate more constituent signal paths, have a number label, to indicate a number of constituent signal paths, and/or have arrows at one or more ends, to indicate primary information flow direction. This, however, should not be construed in a limiting manner. Rather, such added detail may be used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit. Any represented signal lines, whether or not having additional information, may actually comprise one or more signals that may travel in multiple directions and may be implemented with any suitable type of signal scheme, e.g., digital or analog lines implemented with differential pairs, optical fiber lines, and/or single-ended lines.

Example sizes/models/values/ranges may have been given, although embodiments are not limited to the same. As manufacturing techniques (e.g., photolithography) mature over time, it is expected that devices of smaller size could be manufactured. In addition, well known power/ground connections to IC chips and other components may or may not be shown within the figures, for simplicity of illustration and discussion, and so as not to obscure certain aspects of the embodiments. Further, arrangements may be shown in block diagram form in order to avoid obscuring embodiments, and also in view of the fact that specifics with respect to implementation of such block diagram arrangements are highly dependent upon the platform within which the embodiment is to be implemented, i.e., such specifics should be well within purview of one skilled in the art. Where specific details (e.g., circuits) are set forth in order to describe example embodiments, it should be apparent to one skilled in the art that embodiments can be practiced without, or with variation of, these specific details. The description is thus to be regarded as illustrative instead of limiting.

The term “coupled” may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms “first” , “second” , etc. may be used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

As used in this application and in the claims, a list of items joined by the term “one or more of” may mean any combination of the listed terms. For example, the phrases “one or more of A, B or C” may mean A, B, C； A and B； A and C； B and C； or A, B and C.

Those skilled in the art will appreciate from the foregoing description that the broad techniques of the embodiments can be implemented in a variety of forms. Therefore, while the embodiments have been described in connection with particular examples thereof, the true scope of the embodiments should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, specification, and following claims.

Claims

A security-enhanced computing system comprising:

a display to visually present information regarding a digital file；

a file subsystem including storage； and

a trusted environment apparatus communicatively coupled to the file subsystem, the trusted environment apparatus including,

a root key embedded in the trusted environment apparatus；

an authenticator to conduct, based on signed class information from a user, a membership verification of the user with respect to a file class；

a first key deriver communicatively coupled to the authenticator, the first key deriver to generate, if the membership verification is successful, a key encryption key based on the signed class information and the root key； and

a second key deriver communicatively coupled to the first key deriver, the second key deriver to generate a file encryption key based on the key encryption key and context information associated with the digital file.
The system of claim 1, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.
The system of claim 1, wherein the file class is to correspond to a particular authentication group.
The system of claim 1, wherein the context information is to include a hash of the digital file.
The system of any one of claims 1 to 4, wherein the trusted environment apparatus further includes:

an encryptor to use the file encryption key to encrypt the digital file； and

a storage interface to write the encrypted digital file and the context information to the storage.
The system of any one of claims 1 to 4, wherein the trusted environment apparatus further includes:

an encryptor to use the file encryption key to encrypt the digital file； and

a storage interface to write the encrypted digital file and the context information to the storage.
A trusted environment apparatus comprising:

a root key embedded in the trusted environment；

an authenticator to conduct, based on signed class information from a user, a membership verification of the user with respect to a file class；

a first key deriver communicatively coupled to the authenticator, the first key deriver to generate, if the membership verification is successful, a key encryption key based on the signed class information and the root key； and

a second key deriver communicatively coupled to the first key deriver, the second key deriver to generate a file encryption key based on the key encryption key and context information associated with a digital file.
The apparatus of claim 7, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.
The apparatus of claim 7, wherein the file class is to correspond to a particular authentication group.
The apparatus of claim 7, wherein the context information is to include a hash of the digital file.
The apparatus of any one of claims 7 to 10, further including:

an encryptor to use the file encryption key to encrypt the digital file； and

a storage interface to write the encrypted digital file and the context information to storage.
The apparatus of any one of claims 7 to 10, further including:

a storage interface to read the digital file and the context information from storage； and

a decryptor to use the file encryption key to decrypt the digital file.
A method of operating a trusted environment apparatus, comprising:

conducting, based on signed class information from a user, a membership verification of the user with respect to a file class；

generating, if the membership verification is successful, a key encryption key based on the signed class information and a root key embedded in a trusted environment； and

generating a file encryption key based on the key encryption key and context information associated with a digital file.
The method of claim 13, wherein the signed class information includes a public key associated with the file class and a private key signature associated with the file class and the user.
The method of claim 13, wherein the file class corresponds to a particular authentication group.
The method of claim 13, wherein the context information includes a hash of the digital file.
The method of any one of claims 13 to 16, further including:

using the file encryption key to encrypt the digital file； and

writing the encrypted digital file and the context information to storage.
The method of any one of claims 13 to 16, further including:

reading the digital file and the context information from storage； and

using the file encryption key to decrypt the digital file.
At least one computer readable storage medium comprising a set of instructions, which when executed by a computing device, cause the computing device to:

conduct, based on signed class information from a user, a membership verification of the user with respect to a file class；

generate, if the membership verification is successful, a key encryption key based on the signed class information and a root key embedded in a trusted environment； and

generate a file encryption key based on the key encryption key and context information associated with a digital file.
The at least one computer readable storage medium of claim 19, wherein the signed class information is to include a public key associated with the file class and a private key signature associated with the file class and the user.
The at least one computer readable storage medium of claim 19, wherein the file class is to correspond to a particular authentication group.
The at least one computer readable storage medium of claim 19, wherein the context information is to include a hash of the digital file.
The at least one computer readable storage medium of any one of claims 19 to 22, wherein the instructions, when executed, cause the computing device to:

use the file encryption key to encrypt the digital file； and

write the encrypted digital file and the context information to storage.
The at least one computer readable storage medium of any one of claims 19 to 22, wherein the instructions, when executed, cause the computing device to:

read the digital file and the context information from storage； and

use the file encryption key to decrypt the digital file.
A trusted environment apparatus comprising means for performing the method of any one of claims 13 to 16.