How cryptography is used and fails in the real world

J. Alex Halderman (University of Michigan, USA)


J. Alex Halderman is an assistant professor of computer science and engineering at the University of Michigan and the director of Michigan’s Center for Computer Security and Society. He is well known for developing the “cold boot” attack against disk encryption, which altered widespread thinking on security assumptions about the behavior of RAM, influenced computer forensics practice, and inspired leakage-resilient cryptography. A noted expert on electronic voting security, he helped lead the first independent review of the election technology used by half a billion voters in India, which prompted the national government to undertake major technical reforms. In recent work, he exposed widespread flaws in public key generation that compromised the security of 5-10% of Internet hosts serving HTTPS and SSH. His work has won numerous distinctions, including two best paper awards from the USENIX Security conference. He received his Ph.D. in computer science from Princeton University.


Cryptography today is seeing increased real-world adoption through rapid growth  in HTTPS, Bitcoin, and other applications. Yet mistakes in the way these tools  are implemented and used have led to serious vulnerabilities and high-profile compromises. In this talk, I’ll report on the state of deployed crypto based on results from more than 400 Internet-wide scans over the past two years. I’ll explain how global measurement techniques can expose subtle flaws in heterogeneous implementations, and I’ll discuss widespread vulnerabilities, including problems with entropy sources, that compromise an alarming fraction of public key deployments today. Finally, I’ll examine the aftermath of the infamous Heartbleed vulnerability and discuss ways that the world’s response to such crypto disasters can be improved. I’ll conclude with lessons for applied cryptographic practice and for the crypto research community.