Data-Centric Security
Dawn SongUC Berkeley
Collaboration with Lorenzo Martignoni, Stephen McCamant, Pongsin Poosankam, Matei Zaharia, Scott Shenker, Ion Stoica, Vern Paxson, Emil, Elaine Shi, Petros, David Evans
TRANSFORMATION
HARDWARE SYSTEM ARCHITECTURES
SVA
Binary translation and
emulation
Formal methods
Hardware support for isolation
Dealing with malicious hardware
Cryptographic secure computation
Data-centric security
Secure browser appliance
Secure servers
WEB-BASED ARCHITECTURES
e.g., Enforce properties on a malicious OS
e.g., Prevent dataexfiltration
e.g., Enable complex distributed systems, with resilience to hostile OS’s
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 Songwith Lorenzo Martignoni, Stephen McCamant,
Pongsin Poosankam, Matei Zaharia, Scott Shenker, Ion Stoica, Vern Paxson
Motivation
• Sample application: online banking
• Quickly switch your PC to a secure operation mode
• Application provides a normal-looking graphical interface
• But, information security does not depend on your primary OS or any of its software• Application environment is known clean• 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:
• Heavy weight• Management overhead• Multiple general-pupose VMs on one machine require complex
hardware virtualization (e.g., Xen)• Must be careful to keep secure VMs clean (e.g., roll back virtual
disk after session)• How can the bank know you're using a secure VM?
• Want to achieve similar isolation, but • Much lighter weight on client side• Centralize the application logic and administration• Enable a new security abstraction
Cloud Terminal Architecture
General-purpose
OS
Securethin
terminal
Lightweight hypervisor
Trusted Computing Hardware
Cloud Rendering Engine
Application
Virtual desktop server
VM
Encrypted tunnel
Secure Thin Terminal
• Coexists with a general-purpose commodity OS• But completely stand-alone and isolated: when it runs,
the untrusted OS is suspended• Display output:
• Reads encrypted bitmaps from the network, and decrypts and displays them
• Inputs• 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
• Move application logic to centralized servers for ease of administration and protection
• Each user session has its own VM with chosen application
• Virtual desktop server (e.g., VNC) plus encrypting proxy
• Performance optimization• VMs can share disk and memory copy-on-write to minimize
resource usage
• Applications• Standalone• Browser applications
Results from Initial Prototype
• Secure Thin Terminal: only a few KLOC • VNC client and drivers for input, graphics, and network
• Interactive latency (e.g., keystroke echo) low, even with a cloud server in another state
• Scalability for cloud rendering engine:• 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
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
Platform for Private Data
Application:Financial advisor
Privacy evidence
Application:Drug side effect tracker
API
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
TPM &Processor isolation
Platform for Private Data(TCB)
Privacy evidence
Diff. Priv.
Engine
Application
Operations on sensitive data
Info flow tracking
…
Secure data capsules
QueryEngine
PolicyEngine
AuditEngine
Secure Execution Environment
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
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Ruby on Rails CodePolicy Annotations
Secure Web Application
Attach Policies to Data Little developer effort Improved readability
and analyzabilityAutomatically 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
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Example PoliciesAnnotation Meaning
@delete, :admin, :to login Only administrators can delete this object
@edit, pswrd, self.id == user.id, :to login
Only the user may change that user’s password
@create, User, log_create; true
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.
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
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