This undated PRISM intercept from the NSA suggests the agency was unable to decrypt a PGP-encrypted email sent from a Yahoo account: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.
This undated PRISM intercept from the NSA suggests the agency was unable to decrypt a PGP-encrypted email sent from a Yahoo account: see the Der Spiegel story Prying Eyes: Inside the NSA’s War on Internet Security, 28 December 2014.