NSA spurs secrecy.

• Author: Tuccille, J.D.
• Position: Privacy protections - Brief article

Reacting to revelations about the National Security Agency's interception and storage of online data, Twitter announced in November that it is joining other tech companies in implementing "perfect forward secrecy."

While many Internet services already encrypt user communications and other information, this form of encryption separately encodes each session to ensure that snoops who break a code get access to only a snippet of data, not everything belonging to a user. Even when the government obtains a warrant for information, perfect forward secrecy has the potential to limit intrusions rather than providing a skeleton key.

Facebook also plans to implement perfect forward secrecy, and Google has had it in...