Overview
Explore a 23-minute IEEE conference talk that delves into the innovative CoSi protocol, designed to enhance the security and transparency of critical network authorities. Learn how this scalable witness cosigning protocol ensures that authoritative statements are validated and publicly logged by diverse witnesses before client acceptance. Discover how CoSi protects against undetected exploits and misuse of secret keys, offering a robust defense mechanism even against persistent man-in-the-middle attackers. Examine the protocol's ability to scale to thousands of witnesses through signature aggregation and efficient communication trees. Gain insights into CoSi's practical applications in timestamping and logging authorities, and understand its potential to revolutionize trust models in network security.
Syllabus
Intro
Talk Outline
Authority Compromise
Weak Links
Secret Key Portability
Everybody Wants In
Example: Tor Directory Authority
Trust-splitting needs to scale
A First Step: Transparency
Decentralized Witness Cosigning
Schnorr Signature
CoSi Response Phase
Unavailable Witness Servers
Experimental Evaluation
Results: Verification Cost
Results: Collective Signature Size
Existing Transparency Solutions
Other uses of collective signing
Conclusion
Taught by
IEEE Symposium on Security and Privacy