1. Cloud Security
李芮，蒋希坤，崔男
2018年4月

2. A Data Obliviate File System for Intel SGX
Contents
Cloud data 1
TenantGuard 2
A Data Obliviate File System for Intel SGX 3

4. Concerns Where’s data? Who has access? Do you have the right to audit?
Anyone else can see it?
Could the data be duplicated? ……

5. Cloud virtual networks
Data privacy
Liang K, Su C, Chen J, et al. Efficient Multi-Function Data Sharing and Searching Mechanism for Cloud-Based Encrypted Data[C]// ACM on Asia Conference on Computer and Communications Security. ACM, 2016:83-94.
Cloud virtual networks
Majumdar S, Wang Y, Madi T, et al. TenantGuard: Scalable Runtime Verification of Cloud-Wide VM-Level Network Isolation[C]// The Network and Distributed System Security Symposium
Verification
A Ahmad, K Kim, MI Sarfaraz, et al. OBLIVIATE: A Data Oblivious File System for Intel SGX [C]//Network and Distributed Systems Security (NDSS) Symposium 2018

6. A Data Obliviate File System for Intel SGX
Contents 1
Cloud data
TenantGuard 2
A Data Obliviate File System for Intel SGX 3

7. For cloud data Homomorphic encryption For cloud computing Homomorphic
Cloud data share
Cloud data search
Cloud-Based Encrypted Data

8. What’s Homomorphic? (同态)
A way to delegate processing of your data, without giving away access to it. [Gen09]
Example??

9. Example for Homomorphic

10. Application cloud computing
Processing data
Without access to get

12. Comparison for HE

13. Cloud Data share and search

14. Algorithm 𝑺𝒆𝒕𝒖𝒑→(𝒎𝒑𝒌,𝒎𝒔𝒌) 𝑼𝒑𝑻𝑲𝑮𝒆𝒏→ 𝒖𝒑𝒕𝒌 𝒘𝒊→𝒘𝒋 𝑲𝒆𝒚𝑮𝒆𝒏→( 𝒑𝒌 𝑰𝑫 , 𝒔𝒌 𝑰𝑫 )
𝑹𝒆𝑬𝒏𝒄→𝑪𝑻
𝑬𝒏𝒄→𝑪𝑻
𝑼𝒑𝒅𝒂𝒕𝒆→𝑪𝑻
𝑻𝑲𝑮𝒆𝒏→𝑻𝑲
𝑺𝒆𝒂𝒓𝒄𝒉→𝟎/𝟏
𝑹𝒆𝑲𝒆𝒚𝑮𝒆𝒏→ 𝒓𝒌 𝑰𝒅𝒊→𝒊𝒅𝒋, 𝒘𝒊→𝒘𝒋
𝑫𝒆𝒄→𝒎

15. Data search phase

16. keyword description update and C share

17. Data sharing Privacy preservation
allow any system user with valid decryption rights of an encrypted data to share his/her encrypted data to others efficiently and securely
Given either a search token or keyword update token, a cloud server does not know any knowledge of the keyword(s)
Given an original ciphertext or shared (reencrypted) ciphertext, a cloud server does not know any information of the underlying message as well as the keyword description tagged with the ciphertext.

18. Realization – Bilinear Map

19. A Data Obliviate File System for Intel SGX
Contents 1
Cloud data
TenantGuard 2
A Data Obliviate File System for Intel SGX 3

20. Paper Structure
– Background of TenantGuard – Architecture of TenantGuard – Key Ideas of TenantGuard – Application of TenantGuard to OpenStack

21. Highlights

22. Isolation Breaches
Isolation Breaches is one of the Biggest Security Concerns in Cloud.

23. Isolation Breaches
One possible solution is: network isolation verification

24. Challenges of Network Isolation Verification

25. Existing Approaches

26. Network Isolation Verification

27. TenantGuard: Architecture

28. TenantGuard: Architecture

29. TenantGuard: Key Ideas

30. TenantGuard: Key Ideas

31. TenantGuard: Key Ideas

32. Hierarchical Virtual Network Model

33. Hierarchical Virtual Network Model

34. Baseline Approach

35. TenantGuard: Top-Down Verification

36. TenantGuard: Top-Down Verification

37. TenantGuard: Top-Down Verification

38. TenantGuard: Top-Down Verification

39. TenantGuard: Efficient Data Structure

40. TenantGuard: Efficient Data Structure

41. TenantGuard: Efficient Data Structure

42. TenantGuard: Efficient Data Structure

43. TenantGuard: Incremental Verification

44. Application to OpenStack

45. Performance Evaluation

46. Further Performance Improvement

47. Further Performance Improvement

48. Conclusion

49. Cloud data TenantGuard A Data Obliviate File System for Intel SGX
Contents 1
Cloud data 2
TenantGuard
A Data Obliviate File System for Intel SGX 3

50. Trend 1: Security and Privacy Critical Factors in Technology Adoption
Demands for “security” and “privacy” are increasing
Widespread use of Transport Layer Security (TLS)
Popularity of anonymity networks (e.g., Tor)
Use of strong authentication/encryption in WiFi
Expectation on security and privacy impacts design decisions:
Operating system (iOS, Android)
Apps/services (e.g., messenger, adblocker)
Network infrastructure (inter-domain SDN)
I’d like to start by pointing out two big trends. First, security and privacy are becoming critical factors for technology adoption.
Applications and services with enhanced security and privacy features are getting increasingly adopted. And they often impact our design decision.
We see many examples like this in today’s market.

51. Trend 2: Commoditization of Trusted Execution Environment
Trusted Execution Environment (TEE)
Isolated execution: integrity of code, confidentiality
Remote attestation
Commoditization of TEE
Trusted Platform Module (TPM) : Slow performance
ARM TrustZone : Only available for embedded devices
Intel Software Guard Extension (SGX)
1. Native performance
2. Compatibility with x86
The second trend is commoditization of trusted execution environments or TEEs. TEEs provide hardware-based mechanisms for isolated execution and remote attestation. While the idea and implementation has been around for a long time, it had several practical limitation. However, the newly released Intel SGX truly signals the commoditization by lifting off some of the limitations ; it gives native performance to software running in the secure mode and is compatible with x86. Imagine all our laptops and servers on the Cloud supportingTEE. We believe that The commoditization of TEE brings new opportunities for network applications because many network and middlebox applications run on x86.

52. Network Applications + TEE = ?
What impact does TEE have on networking?
Previous efforts: Adopting TEE to cloud platform
Haven [OSDI’14] : Protects applications from an untrusted cloud
VC3 [S&P’15] : Trustworthy data analytics in the cloud
Network
Applications
TEE
Enhanced security
New design space
New functionality
Intel SGX

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73. 谢谢！