Problems with Current Crypto Implementation
Academic Paper: “Imperfect Forward Secrecy: How Diffie-Hellman Fails in Practice” (pdf; 13 pages), published earlier this year, but presented at a recent conference
General Explanation (by two of the fourteen co-authors of the academic paper): How is NSA Breaking So Much Crypto? – Freedom to Tinker
EFF’s Two Part Explainer: Logjam, Part 1: “Why the Internet is Broken Again” and Logjam, Part 2: “Did the NSA Know the Internet Was Broken”
EFF’s Practical Advice: How to Protect Yourself from NSA Attacks on 1024-bit DH
Bruce Schneier: Breaking Diffie-Hellman with Massive Precomputation (Again) and his previous post The Logjam (and Another) Vulnerability against Diffie-Hellman Key Exchange