[PPT] - OpenSGX: An Open Platform for SGX Research Prerit Jain, Soham Desai, PowerPoint Presentation

SLIDE 1

OpenSGX: An Open Platform for SGX Research

Prerit Jain, Soham Desai, Seongmin Kim*, Ming-Wei Shih, JaeHyuk Lee, Changho Choi, Youjung Shin, Taesoo Kim, Brent Byunghoon Kang, Dongsu Han

1

SLIDE 2

Trusted Execution Environment (TEE)

2

Hardware technologies for trusted computing

– Isolated execution: integrity of code, confidentiality – To protect application from untrusted platform

SLIDE 3

Trusted Execution Environment (TEE)

3

Hardware technologies for trusted computing

– Isolated execution: integrity of code, confidentiality – To protect application from untrusted platform

SLIDE 4

Trusted Execution Environment (TEE)

4

Hardware technologies for trusted computing

– Isolated execution: integrity of code, confidentiality – To protect application from untrusted platform

SLIDE 5

Trusted Execution Environment (TEE)

5

Hardware technologies for trusted computing

– Isolated execution: integrity of code, confidentiality – To protect application from untrusted platform

SLIDE 6

Trusted Execution Environment (TEE)

6

Hardware technologies for trusted computing

– Isolated execution: integrity of code, confidentiality – To protect application from untrusted platform

Practical limitations of TEEs

– Trusted Platform Module (TPM) : Poor performance – ARM TrustZone : Compatibility (only for embedded devices)

SLIDE 7

Intel SGX

7

An extension of x86 Instruction Set Architecture (ISA)

– Offers native performance, Compatibility with x86 – Application keeps its data/code inside the “enclave”

Operating System (untrusted) Application (untrusted) Enclave Skylake CPU

SLIDE 8

Intel SGX

8

An extension of x86 Instruction Set Architecture (ISA)

– Offers native performance, Compatibility with x86 – Application keeps its data/code inside the “enclave”

Operating System (untrusted) Application (untrusted) Enclave

Data Code

Skylake CPU

SLIDE 9

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

9

Address Space Enclave Physical Memory EPC

Encrypted code/data

CPU Package

SLIDE 10

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

10

Address Space Enclave Physical Memory EPC

Encrypted code/data

CPU Package Memory Encryption Engine (MEE)

SLIDE 11

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

11

Address Space Enclave Physical Memory EPC

Encrypted code/data

CPU Package Memory Encryption Engine (MEE)

SLIDE 12

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

12

Address Space Enclave Physical Memory EPC

Encrypted code/data

CPU Package Memory Encryption Engine (MEE) Processor Key

SLIDE 13

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

13

Address Space Enclave Physical Memory EPC

Encrypted code/data

CPU Package Memory Encryption Engine (MEE) Snooping Processor Key

SLIDE 14

Intel SGX 101: Isolated Execution

Smallest attack surface by reducing TCB (App + processor)
Protect app’s secret from untrusted privilege software

14

Address Space Enclave Access from OS/VMM Physical Memory EPC

Encrypted code/data

CPU Package Memory Encryption Engine (MEE) Snooping Processor Key

SLIDE 15

Intel SGX 101: Remote attestation

15 15

Attest an application on remote platform

– Check the integrity of enclave (hash of code/data pages) – Verify whether enclave is running on real SGX CPU – Can establish a “secure channel” between enclaves

Application Enclave

Quoting Enclave

Remote platform User platform

1. Request

Application Challenger Enclave Attestation Verification

EPID key Ephemeral

2. Create REPORT
3. Sign with

EPID group key (Create QUOTE)

4. Send

QUOTE

5. Verify

SLIDE 16

Intel SGX 101: Remote attestation

16 16

Attest an application on remote platform

– Check the integrity of enclave (hash of code/data pages) – Verify whether enclave is running on real SGX CPU – Can establish a “secure channel” between enclaves

Application Enclave

Quoting Enclave

Remote platform User platform

1. Request

Application Challenger Enclave Attestation Verification

EPID key Ephemeral

2. Create REPORT
3. Sign with

EPID group key (Create QUOTE)

4. Send

QUOTE

5. Verify

Intel SGX brings new opportunities for enhancing security of applications

SLIDE 17

SGX Research: Current Status

Pioneering research: Adopting SGX on cloud computing

(Haven [OSDI14], VC3 [S&P15])

Confidentiality verification of SGX program

(Moat [CCS15])

Adopts SGX on networking [HotNets15]

17

SLIDE 18

SGX Research: Current Status

However, software technologies for SGX lag behind their

hardware counterpart

18

SGX CPU and SDK is now available! But..

Specification for SGX [revision 1 & 2] is not fully available
n the SGX hardware (only functionalities in revision 1)
SGX technology has a complex license model

SLIDE 19

OpenSGX: Design Goal

19

Offers a complete platform for SGX research

– To explore software and hardware design space of SGX – To develop and evaluate SGX-enabled applications

SLIDE 20

OpenSGX: Design Goal

20

Offers a complete platform for SGX research

– To explore software and hardware design space of SGX – To develop and evaluate SGX-enabled applications

Fills non-trivial issues on SGX software components

– Support for system software and user-level APIs – Familiar programming model and interface – Secure design to defend against potential attack vectors (e.g., Iago attacks)

SLIDE 21

OpenSGX: Design Goal

21

Offers a complete platform for SGX research

– To explore software and hardware design space of SGX – To develop and evaluate SGX-enabled applications

Fills non-trivial issues on SGX software components

– Support for system software and user-level APIs – Familiar programming model and interface – Secure design to defend against potential attack vectors (e.g., Iago attacks)

Non goal : security guarantee

SLIDE 22

Binary Translation

OpenSGX: Approach

22

Using userspace emulation of QEMU

– Binary translation to support SGX instructions – QEMU helper routine to implement complex instructions Helper routine

Set registers
Operates

SGX instructions

QEMU Host (single address space)

Wrapper

Lib Stack Heap

Enclave

Code Data

EPC EPC EPC EPC EPC

… …

enclu(){ …

asm(“.byte 0x0f” “.byte 0x01” “.byte 0xd7” “rax=entry”

… }

Entry point

… if(opcode == 0x0f01d7) { helper_enclu(); } …

RIP

SLIDE 23

Binary Translation

OpenSGX: Approach

23

Using userspace emulation of QEMU

– Binary translation to support SGX instructions – QEMU helper routine to implement complex instructions Helper routine

Set registers
Operates

SGX instructions

QEMU Host (single address space)

Wrapper

Lib Stack Heap

Enclave

Code Data

EPC EPC EPC EPC EPC

… …

enclu(){ …

asm(“.byte 0x0f” “.byte 0x01” “.byte 0xd7” “rax=entry”

… }

Entry point

… if(opcode == 0x0f01d7) { helper_enclu(); } …

RIP

SLIDE 24

OpenSGX: Component Overview

24

Emulated SGX hardware

SGX QEMU (HW emulation)

SLIDE 25

OpenSGX: Component Overview

25

Emulated SGX hardware

SGX OS Emulation SGX QEMU (HW emulation)

OS emulation layer

SLIDE 26

OpenSGX: Component Overview

26

Emulated SGX hardware

SGX OS Emulation SGX QEMU (HW emulation) SGX Libraries

Trampoline Stub

OS emulation layer
OpenSGX user library

SLIDE 27

OpenSGX: Component Overview

27

Emulated SGX hardware

SGX OS Emulation SGX QEMU (HW emulation) OpenSGX toolchain SGX Libraries

Trampoline Stub

OS emulation layer
OpenSGX user library
OpenSGX toolchain

SLIDE 28

OpenSGX: Component Overview

28

Emulated SGX hardware
Enclave loader

SGX OS Emulation SGX QEMU (HW emulation) OpenSGX toolchain Enclave loader SGX Libraries

Trampoline Stub

Runtime library

OS emulation layer
OpenSGX user library
OpenSGX toolchain

SLIDE 29

OpenSGX: Component Overview

29

Emulated SGX hardware
Enclave loader

SGX OS Emulation SGX QEMU (HW emulation) OpenSGX toolchain Enclave loader SGX Libraries

Trampoline Stub

Runtime library Enclave Debugger Performance Monitor

OS emulation layer
OpenSGX user library
OpenSGX toolchain
Enclave debugger
Performance monitor

SLIDE 30

OpenSGX: Component Overview

30

Emulated SGX hardware
Enclave loader

SGX OS Emulation SGX QEMU (HW emulation) Enclave Program OpenSGX toolchain Enclave loader SGX Libraries

Trampoline Stub

Runtime library Enclave Debugger Performance Monitor

OS emulation layer
OpenSGX user library
OpenSGX toolchain
Enclave debugger
Performance monitor

SLIDE 31

OpenSGX: Component Overview

31

Emulated SGX hardware
Enclave loader

SGX OS Emulation SGX QEMU (HW emulation) Enclave Program OpenSGX toolchain Enclave loader SGX Libraries

Trampoline Stub

Runtime library Enclave Debugger Performance Monitor

OS emulation layer
OpenSGX user library
OpenSGX toolchain
Enclave debugger
Performance monitor

void enclave_main(){ char *hello = “hello sgx!\n”; sgx_enclave_wriate(hello, strlen(hello)); sgx_exit(NULL); } $ opensgx hello.sgx hello.conf hello sgx! Code enclave_main() Data “hello sgx\n” 0x0000 EPC1 0x1000 EPC2 Entry point : SigStruct: …

SLIDE 32

OpenSGX: Component Overview

32

Emulated SGX hardware
Enclave loader

  

SGX OS Emulation SGX QEMU (HW emulation) Enclave Program OpenSGX toolchain Enclave loader SGX Libraries

Trampoline Stub

Runtime library Enclave Debugger Performance Monitor

OS emulation layer
OpenSGX user library
OpenSGX toolchain
Enclave debugger
Performance monitor

void enclave_main(){ char *hello = “hello sgx!\n”; sgx_enclave_wriate(hello, strlen(hello)); sgx_exit(NULL); } $ opensgx hello.sgx hello.conf hello sgx! Code enclave_main() Data “hello sgx\n” 0x0000 EPC1 0x1000 EPC2 Entry point : SigStruct: …

SLIDE 33

Hardware Emulation

33

Emulates all data structures(e.g., EPCM) and processor key
EPC Memory management

– Direct mapping on virtual memory – Access protection: Instrument memory access

SLIDE 34

Hardware Emulation

34

Emulates all data structures(e.g., EPCM) and processor key
EPC Memory management

– Direct mapping on virtual memory – Access protection: Instrument memory access Virtual address space

SLIDE 35

Hardware Emulation

35

Emulates all data structures(e.g., EPCM) and processor key
EPC Memory management

– Direct mapping on virtual memory – Access protection: Instrument memory access

EPC_begin EPC_end

Virtual address space

SLIDE 36

Hardware Emulation

36

Emulates all data structures(e.g., EPCM) and processor key
EPC Memory management

– Direct mapping on virtual memory – Access protection: Instrument memory access

EPC_begin EPC_end enclave_begin enclave_end

Virtual address space

2. Prohibit others enclaves’

EPC to current enclave’s EPC

1. Prohibit access

from host to EPC

SLIDE 37

Hardware Emulation

37

Emulates all data structures(e.g., EPCM) and processor key
EPC Memory management

– Direct mapping on virtual memory – Access protection: Instrument memory access

EPC_begin EPC_end enclave_begin enclave_end

QEMU’s translation routine

… Case (Load | Store) { } …

Virtual address space

2. Prohibit others enclaves’

EPC to current enclave’s EPC

1. Prohibit access

from host to EPC

SLIDE 38

Instruction Support

38

OpenSGX supports most instructions specified

– 21 out of 24 instructions – Except for debugging related instructions (e.g., EDBGRD) – Instead, it offers rich environment for debugging since it is a “software emulator” (e.g., GDB stub)

SLIDE 39

Instruction Support

39

OpenSGX supports most instructions specified

– 21 out of 24 instructions – Except for debugging related instructions (e.g., EDBGRD) – Instead, it offers rich environment for debugging since it is a “software emulator” (e.g., GDB stub)

Provides simple C APIs which wraps assembly code

– User-level instructions (ENCLU) : accessible to user-level APIs – Super-level instructions (ENCLS) : Requires system support

SLIDE 40

OS Emulation Layer

40

Emulate OS to execute the privileged SGX instructions

– Bootstrapping (EPC allocation) – Enclave initialization & page translation – Dynamic EPC page allocation System call Description

sys_sgx_init() Allocate EPC memory region sys_init_enclave() Create an enclave, Add and measure EPC pages sys_add_epc() Allocates a new EPC page to the running enclave sys_stat_enclave() Obtains the enclave statistics

SLIDE 41

OS Emulation Layer

41

Emulate OS to execute the privileged SGX instructions

– Bootstrapping (EPC allocation) – Enclave initialization & page translation – Dynamic EPC page allocation System call Description

sys_sgx_init() Allocate EPC memory region sys_init_enclave() Create an enclave, Add and measure EPC pages sys_add_epc() Allocates a new EPC page to the running enclave sys_stat_enclave() Obtains the enclave statistics

Planning to extend the emulated OS for the system-level layer

SLIDE 42

Stub and Trampoline Interface

“A strict and narrow interface to handle enclave-host communication using shared data/code”

42

SLIDE 43

Stub and Trampoline Interface

“A strict and narrow interface to handle enclave-host communication using shared data/code”

43

Enclave

Code Heap Lib

Emulated OS Wrapper

Trampoline

(Shared) Stub : Shared data to specify the function code and arguments Trampoline : Shared code to call user-level APIs in the wrapper

Stub

SLIDE 44

Stub and Trampoline Interface

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

44

Enclave

Code Heap Lib

Emulated OS Wrapper

Trampoline

(Shared)

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

fcode mcode argument1 heap_end

Stub : Shared data to specify the function code and arguments Trampoline : Shared code to call user-level APIs in the wrapper

… malloc(100); … malloc(){ … sgx_exit(tram); … }

Stub

SLIDE 45

Stub and Trampoline Interface

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

45

Enclave

Code Heap Lib

Emulated OS Wrapper

Trampoline

(Shared)

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

fcode mcode argument1 heap_end

Stub : Shared data to specify the function code and arguments Trampoline : Shared code to call user-level APIs in the wrapper

Heap

… malloc(100); … malloc(){ … sgx_exit(tram); … }

Stub

FULL!

SLIDE 46

Stub and Trampoline Interface

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

46

Enclave

Code Heap Lib

Emulated OS Wrapper

Trampoline

(Shared)

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

fcode mcode argument1 heap_end

Stub : Shared data to specify the function code and arguments Trampoline : Shared code to call user-level APIs in the wrapper

Heap

… malloc(100); … malloc(){ … sgx_exit(tram); … }

<Specification> fcode : FUNC_MALLOC mcode : EAUG size: 100

Stub

FULL!

SLIDE 47

Trampoline and Stub Interface

Stub

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

47

Enclave

Code

…

malloc(100);

…

Heap Lib

malloc(){ … sgx_exit(tram); … }

Emulated OS

Trampoline

(Shared)

heap_end

EEXIT

FUNC_MALLOC EAUG 100

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

Wrapper

alloc_tramp() { … sys_add_epc(); … }

User-level APIs to request system calls

SLIDE 48

Trampoline and Stub Interface

Stub

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

48

Enclave

Code

…

malloc(100);

…

Heap Lib

malloc(){ … sgx_exit(tram); … }

Emulated OS

int sys_add_epc() { encls(EAUG, …); …

Trampoline

(Shared)

Call EAUG heap_end

EEXIT

FUNC_MALLOC EAUG 100

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

Wrapper

alloc_tramp() { … sys_add_epc(); … }

User-level APIs to request system calls

System Call

SLIDE 49

Trampoline and Stub Interface

Stub

…

“A strict and narrow interface to handle enclave-host communication using shared data/code”

49

Enclave

Code

…

malloc(100);

…

Heap Lib

malloc(){ … sgx_exit(tram); … }

Emulated OS

int sys_add_epc() { encls(EAUG, …); …

Trampoline

(Shared)

Call EAUG

ERESUME EEXIT

FUNC_MALLOC EAUG 100

… if (fcode == FUNC_MALLOC) alloc_tramp(); …

Wrapper

alloc_tramp() { … sys_add_epc(); … }

User-level APIs to request system calls

System Call

heap_end+4K

SLIDE 50

Evaluation: Tor Network

50

Redesigns non-trivial application to use OpenSGX
Tor : volunteer-based anonymity network

SLIDE 51

Evaluation: Tor Network

51

Redesigns non-trivial application to use OpenSGX
Tor : volunteer-based anonymity network

“Defend possible attacks on Tor components when they are compromised by adversaries”

SLIDE 52

Evaluation: Tor Network

52

Redesigns non-trivial application to use OpenSGX
Tor : volunteer-based anonymity network
Here, defense against network-level attacks on Tor is
ut of scope

“Defend possible attacks on Tor components when they are compromised by adversaries”

SLIDE 53

SGX-enabled Tor Design

53

Design goal

– Protect data/code from adversary – Reducing Trusted Computing Base Enclave Exit node (or directory server) Separation

SLIDE 54

SGX-enabled Tor Design

54

Design goal

– Protect data/code from adversary – Reducing Trusted Computing Base Enclave Exit node (or directory server)

Key Relay table

gen_key(){ … } encrypt(){ … }

Core operations (e.g., key creation, encryption, decryption, …)

Separation

SLIDE 55

SGX-enabled Tor Design

55

Design goal

– Protect data/code from adversary – Reducing Trusted Computing Base Enclave Exit node (or directory server)

Key Relay table

gen_key(){ … } encrypt(){ … }

Core operations (e.g., key creation, encryption, decryption, …)

Separation Interaction Rest of Tor operations

1. Send/receive packets
2. Initialize data structures

…

SLIDE 56

Enclave Other Tor nodes

SGX-enabled Tor Design

56

Design goal

– Protect data/code from adversary – Reducing Trusted Computing Base Enclave Exit node (or directory server)

Key Relay table

gen_key(){ … } encrypt(){ … }

Core operations (e.g., key creation, encryption, decryption, …)

Separation Interaction Rest of Tor operations

1. Send/receive packets
2. Initialize data structures

…

Remote Attestation Interaction

SLIDE 57

Performance Profiling

57

Code Data Total OpenSSL 271 89 360 SgxLib 3 1 4 Tor 4 1 5 Total 278 91 369

(Unit: Number of pages)

Required EPC : Less than 2MB

Performance profiling of Tor exit node

– Using OpenSGX performance monitor

200 400 600 800 1000 1200

# of instructions (M)

Key generation Consensus creation Circuit establishment & Service Total

SLIDE 58

OpenSGX: Current Status

58

Available at github, released in May 2015

– Available in https://github.com/sslab-gatech/opensgx – 7 Contributors (Gatech, KAIST, Two sigma, MITRC, …) – 31 unique cloners, 1,645 Views (Until January, 2016)

What’s next?

– Binary compatibility with Intel SGX hardware – Implement unsupported functionalities (e.g., multi-threading)

Our current community

SLIDE 59

Our Early Lessons on SGX

59

Misconceptions on SGX

– SGX for desktop-like environment : Needs secure I/O channel (integration with hardware technology such as Intel IPT) – Need EPID support for the remote attestation

SLIDE 60

Our Early Lessons on SGX

60

Misconceptions on SGX

– SGX for desktop-like environment : Needs secure I/O channel (integration with hardware technology such as Intel IPT) – Need EPID support for the remote attestation

Malicious use of Intel SGX

– Malware might be possible by abusing the isolation property – Fails on traditional signature-based AV programs

SLIDE 61

Conclusion

61

We design and implement OpenSGX, fully functional and

instruction-compatible SGX emulator

SLIDE 62

Conclusion

62

We design and implement OpenSGX, fully functional and

instruction-compatible SGX emulator

As a showcasing application, we develop SGX-enabled

Tor to enhance the security and privacy

SLIDE 63

Conclusion

63

We design and implement OpenSGX, fully functional and

instruction-compatible SGX emulator

As a showcasing application, we develop SGX-enabled

Tor to enhance the security and privacy

OpenSGX offers opportunities to explore all components
f SGX research

– Hardware semantics (e.g., encryption scheme of MEE) – System software, enclave loader and user-level APIs – Redesigning unforeseen security applications (e.g., Tor)

SLIDE 64

64

Thanks! Any Questions?

SLIDE 65

SGX Threat Model

65

“An adversary has control over all software components (including OS and hypervisor) and hardware except the CPU package”

Protection against denial-of-service is out of scope

SLIDE 66

Comparison: Intel SGX vs OpenSGX

66

Intel SGX OpenSGX Type Hardware Software Emulator Instructions 16 ENCLS, 8 ENCLU 13 ENCLS, 8 ENCLU (Except debugging) Data structures Specified ○ Paging Page table Direct mapping System software Not specified User level emulation User level APIs SDK is available (Only for Windows) ○

SLIDE 67

OpenSGX User Library

67

Challenge 1: Facilitate the enclave programming

– Custom in-enclave library : APIs for user-level SGX instructions – Porting standard C library (glibc)

Challenge 2: Minimize attack surface between

enclave and the potentially malicious host process

– Function call relies on OS features will break an execution of enclave programs – Such functions open up new attack surfaces (e.g., Iago attacks)

SLIDE 68

Enclave

Defense against Iago attacks

68

Iago attacks [ASPLOS’13] : Malicious OS tries to

subvert trusted application by incorrect behavior

ex) adds incorrect EPC page for heap

… malloc(); … Application In-enclave Lib

Emulated OS Wrapper

Stub

heap_end cur_heap_ptr

void *malloc(int size){ if(cur_heap_ptr == heap_end) { stub->mcode = EAUG; exit(trampoline); }

Trampoline

malloc_tramp() { sys_add_epc(); } enclu(EACCEPT, …); int sys_add_epc() { … }

Bad EPC page Detect!

SLIDE 69

Memory State of OpenSGX Program

69

SGX OS Emulation QEMU SGX

User process (single address space)

ENCLS (e.g., EINIT)

Package Info

Entry point Measurement Key …

SGX Lib

Trampoline Stub

Wrapper

Lib Stack Heap

Enclave Program

Code Data

EPC EPC EPC EPC EPC

… …

Privilege boundary System calls boundary

ENCLU (e.g., EENTER) ENCLU (e.g., EEXIT) System call (e.g., sys_sgxinit())

SLIDE 70

Attacks on Tor Components

Tor network : uses 3-hop onion routing

– Directory servers : Advertise available onion routers (ORs), vote for bad exit nodes

Entry Relay Exit

When exit node is compromised, (unless end-to-end encryption is used)

1. Snooping or tampering of the plain-text
2. Break of anonymity : Bad apple attack

70

Directory servers Tor client Destination

Tor network

SLIDE 71

Attacks on Tor Components

Tor network : uses 3-hop onion routing

– Directory servers : Advertise available onion routers (ORs), vote for bad exit nodes Directory servers Tor client Destination

Entry Relay Exit

When directory servers are compromised,

1. Tie-breaking attacks while voting
2. Admission of malicious ORs

71

Tor network

SLIDE 72

Performance Profiling: CPU cycles

72

3000 6000 9000 12000 15000 18000

# of CPU cycles (M)

Key generation Consensus creation Circuit establishment & Service Total

200 400 600 800 1000 1200

# of CPU cycles (M)

OpenSGX Native QEMU OpenSGX Native QEMU

2.8x 2.7x

ENCLU(EEXIT, ERESUME) calls
In-enclave library code to handle stub & trampoline interface

SLIDE 73

Performance Profiling: TCB

Required EPC size: Less than 2MB for each process
TCB size : 54% smaller than compared to Tor code base

73

Code Data Total OpenSSL 270 88 358 SgxLib 3 1 4 Tor 3 1 4 Total 276 90 366 Code Data Total OpenSSL 271 89 360 SgxLib 3 1 4 Tor 4 1 5 Total 278 91 369

(Unit: Number of pages)

SLIDE 74

OpenSGX implementation

74

OpenSGX is an open source project!

– Modified lines of code : 19K – First released in May, 2015 – 7 Contributors (Gatech, KAIST) – 31 unique cloners, 1,645 Views (Until January, 2016) – Available at https://github.com/sslab-gatech/opensgx.git