Transcript Platform for Private Data and Privacy Evidence
Data-Centric Security
Dawn Song UC Berkeley
Collaboration with Lorenzo Martignoni, Stephen McCamant, Pongsin Poosankam, Matei Zaharia, Scott Shenker, Ion Stoica, Vern Paxson, Emil, Elaine Shi, Petros, David Evans
SVA Cryptographic secure computation Binary translation and emulation e.g., Enforce properties on a malicious OS Data-centric security Formal methods TRANSFORMATION Secure browser appliance Hardware support for isolation Dealing with malicious hardware HARDWARE e.g., Prevent data exfiltration Secure servers WEB-BASED ARCHITECTURES SYSTEM ARCHITECTURES e.g., Enable complex distributed OS’s systems, with resilience to hostile
Outline
• • Data-centric security: protecting the data directly instead of network or host-based protection Three examples – Cloud-terminal: providing trusted input/output – Platform for private data – Secure web applications: GuardRails
The Cloud Terminal Architecture for End-to-End Secure Applications
Dawn Song
with Lorenzo Martignoni, Stephen McCamant, Pongsin Poosankam, Matei Zaharia, Scott Shenker, Ion Stoica, Vern Paxson
Motivation
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Sample application: online banking
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Quickly switch your PC to a secure operation mode
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Application provides a normal-looking graphical interface
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But, information security does not depend on your primary OS or any of its software
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Application environment is known clean
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Secure even if commodity OS is compromised by malware
Strawman Approach: one VM per app • • •
Possible approach: one VM per secure app Pro: strong isolation Cons:
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Heavy weight
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Management overhead
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Multiple general-pupose VMs on one machine require complex hardware virtualization (e.g., Xen)
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Must be careful to keep secure VMs clean (e.g., roll back virtual disk after session)
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How can the bank know you're using a secure VM?
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Want to achieve similar isolation, but
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Much lighter weight on client side
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Centralize the application logic and administration Enable a new security abstraction
Cloud Terminal Architecture
General purpose OS Secure thin terminal Lightweight hypervisor Trusted Computing Hardware VM Application Virtual desktop server Cloud Rendering Engine Encrypted tunnel
Secure Thin Terminal
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Coexists with a general-purpose commodity OS But completely stand-alone and isolated: when it runs, the untrusted OS is suspended Display output:
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Reads encrypted bitmaps from the network, and decrypts and displays them Inputs
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Reads keyboard and mouse events, encrypts and sends them on the network Lightweight hypervisor enforces isolation Trusted boot using a TPM allows remote attestation, proving the STT is running unmodified on the bare hardware
Cloud Rendering Engine
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Move application logic to centralized servers for ease of administration and protection
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Each user session has its own VM with chosen application
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Virtual desktop server (e.g., VNC) plus encrypting proxy
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Performance optimization
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VMs can share disk and memory copy-on-write to minimize resource usage
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Applications
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Standalone
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Browser applications
Initial Prototype
Results from Initial Prototype
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Secure Thin Terminal: only a few KLOC
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VNC client and drivers for input, graphics, and network
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Interactive latency (e.g., keystroke echo) low, even with a cloud server in another state
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Scalability for cloud rendering engine:
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A single commodity server can support more than 100 simultaneous rendering VMs
Outline
• • Data-centric security: protecting the data directly instead of network or host-based protection Three examples – Cloud-terminal: providing trusted input/output – Platform for private data – Secure web applications: GuardRails
Motivating Applications
Protecting users’ data is an intricate issue!
• Apps selling your data • Inadvertent disclosure – AOL search log scandal – Netflix contest • Malware and software compromise – RockYou password leakage • Insider attack – Google incident
Platform for Private Data
• • • • • Provide desired services in the cloud while ensuring security and privacy of customers’ data Provide privacy & trust evidence – Customer does not just rely on trust on service provider Provide trustworthy audit trails – For forensics, provenance, accountability, dispute General architecture for broad applicability Practical performance & usability
Platform for private data and privacy evidence
Privacy evidence Application: Financial advisor Application: Drug side effect tracker API Platform for Private Data
Architecture
• • • • • • • Secure data capsule – Data encrypted at rest – Security policy attached to data Trusted computing hardware provides root of trust Secure execution environment – Data capsule only decrypted in secure execution environment – Only authorized code can access and operate on data New programming model for privacy-aware applications Support for legacy applications – Program analysis and information flow Advanced engines for database queries and privacy preserving data analytics Secure auditing
Application Application Info flow tracking Operations on sensitive data Secure Execution Environment Privacy evidence Diff. Priv.
Engine Query Engine Policy Engine Audit Engine Platform for Private Data (TCB) TPM & Processor isolation Secure data capsules …
Outline
• • Data-centric security: protecting the data directly instead of network or host-based protection Three examples – Cloud-terminal: providing trusted input/output – Platform for private data – Secure web applications: guardrails
Ruby on Rails Code
Policy Annotations
Attach Policies to Data Little developer effort Improved readability and analyzability
Secure Web Application
Automatically enforce policies throughout application Jonathan Burket, Patrick Mutchler, Michael Weaver, Muzzammil Zaveri, David Evans. GuardRails: A Data-Centric Web Application Security Framework. To appear in USENIX WebApps 2011.
OWASP AppSec DC 20
Example Policies
Annotation @ delete , :admin , :to login @ edit , pswrd, self.id == user.id
, :to login @ create , User, log_create; true Meaning
Only administrators can delete this object Only the user may change that user’s password Whenever a User object is created, write to log Policies are attached to classes or individual fields. Can perform arbitrary checking and actions based on read , edit , append , create , destroy events.
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Conclusion
• • Data-centric security: protecting the data directly instead of network or host-based protection Three examples – Cloud-terminal: providing trusted input/output – Platform for private data – Secure web applications: GuardRails