American and French officials say there is still no definitive evidence to back up their presumption that the terrorists who massacred 129 people in Paris used new, difficult-to-crack encryption technologies to organize the plot. But in interviews, Obama administration officials say the Islamic State has used a range of encryption technologies over the past year and a half, many of which defy cracking by the National Security Agency. Other encryption technologies, the officials hint, are less secure than terrorist and criminal groups may believe, and clearly they want to keep those adversaries guessing which ones the N.S.A. has pierced.
ORIGINAL SOURCE: NY Times