3. Introduction
Nymble
Properties
System Architecture
Security Model
Limitations
Conclusion
Nymble Blocking System 3
4. Anonymous network
o IP hiding facilities
o Polipo, Tor, USAIP
Users misuses this network for abuse
They deface popular websites
Websites cannot blacklist individual IP
address
They blacklist entire anonymizing network
Nymble Blocking System 4
5. In pseudonymous credential systems
Users are added to a blacklist
Weak in anonymity
In anonymous credential system
Group signatures
Lacks scalability
Nymble Blocking System 5
6. A system that allows websites to selectively
blacklist users of anonymizing networks.
Blocks user without user's IP-address.
Legitimate users enjoy anonymity.
Blacklisted users got blocked for future
connections.
Previous connections remain unlinkable.
Nymble Blocking System 6
13. Aims four security goals
Blacklistability
Rate-limiting assures
Nonframeability
Anonymity
Nymble Blocking System 13
14. Sybil attack
Mimics IP based blocking
Availability of multiple IP address helps
users circumvent the system
Nymble Blocking System 14
15. Nymble is comprehensive credential system.
Add a layer of accountability to any publicly known
anonymizing network.
Servers blacklist misbehaving users maintaining their
privacy.
Increase the mainstream acceptance of anonymizing
network.
Nymble Blocking System 15