Logjam: Diffie-Hellman, discrete logs, the NSA, and you

J. Alex Halderman and Nadia Heninger

Earlier this year, we discovered that Diffie-Hellman key
exchange – cornerstone of modern cryptography – is less
secure in practice than the security community believed. In this
talk, we’ll explain how the NSA is likely exploiting this weakness to
allow it to decrypt connections to at least 20% of HTTPS websites, 25% of SSH servers, and 66% of IPsec VPNs.