On November 16th, 2004 — π years after arriving in Oxford — I submitted my doctoral thesis. My mind wasn't really on my thesis though; I was thinking about an issue I had noticed in recent Intel CPUs: The "Hyper-Threading" (simultaneous multithreading) feature they introduced in 2002 could leak information between execution threads via the cache state.There was a joke at the time that although the National Security Agency had opened up in recent years and started taking their defensive role more seriously, the one aspect of cryptography which they would never discuss publicly was side channel attacks — and this itself constituted a side channel, revealing the importance they attributed to the field. Being active in computer security, and recognizing that the NSA knew a few things about the topic, my immediate priority was to determine whether the information leakage I had identified was sufficient to construct a practical cryptographic side channel. By mid-December I had a proof-of-concept exploit which stole enough bits of an RSA private key for the entire key to be reconstructed, and I turned my…
The Duty of a Scholar
In short
In late 2004, the researcher developed a working proof-of-concept exploit that extracted enough RSA private key bits across threads to fully compromise the encryption key. The academic dedicated six months to an extensive coordinated disclosure, temporarily halting thesis revisions and postponing career opportunities. Intel attempted to block the research by pressuring Yahoo, but the company lacked authority over the non-employee researcher. The findings were formally unveiled alongside vendor patches at the BSDCan conference on May 13, 2005.
Key points
- Hardware cache states in Intel Hyper-Threading technology exposed critical cryptographic…: Hardware cache states in Intel Hyper-Threading technology exposed critical cryptographic secrets to side-channel leakage across threads.
- Coordinated vulnerability disclosure required six months of dedicated outreach to give op…: Coordinated vulnerability disclosure required six months of dedicated outreach to give operating system vendors time to issue patches.
- Personal circumstances, such as living rent-free with family, provided the financial flex…: Personal circumstances, such as living rent-free with family, provided the financial flexibility necessary to complete the disclosure process.