Twitter fires up stronger, anti-snooping encryption for its millions of twits
Crypto-boffinry to keep network traffic secret even if private keys swiped
Twitter says it has rolled out stronger encryption to safeguard its users' connections from eavesdroppers.
The micro-blogging ad-pusher said it has switched on "forward secrecy" for traffic to and from its desktop and mobile websites and its app interface; this goes beyond the protections afforded by traditional HTTPS.
Specifically, Twitter says it is now using the Elliptic Curve Diffie-Hellman (ECDHE) cipher suites. Simply put, these attempt to thwart a third party from decrypting intercepted network packets even if Twitter is later compromised or pressured by g-men into hand over its private keys. This is done by generating a randomized per-session key that's shared between the browser (or app) and Twitter's servers without them exchanging the key in full, even encrypted.
"On top of the usual confidentiality and integrity properties of HTTPS, forward secrecy adds a new property," Twitter security engineer Jacob Hoffman-Andrews said in a blog post.
"If an adversary is currently recording all Twitter users’ encrypted traffic, and they later crack or steal Twitter’s private keys, they should not be able to use those keys to decrypt the recorded traffic."
According to Twitter, as much as 75 per cent of its internet traffic is already established using ECDHE; the remaining 25 per cent comes from older third-party clients that do not support the key agreement protocol.
While Twitter did not mention the NSA specifically, the company underscored the need of users to maintain strongly secured connections and protect against possible surveillance by a third party that could tap into a network or listen in on a session.
Such snooping tactics were found to have been employed by the NSA to collect data from the internet's backbone fibre cabling and the lines connecting major data centers. In the wake of NSA whistleblower Edward Snowden's revelations, a number of web service providers are stepping up encryption on their packets.
Hoffman-Andrews suggested that the use of security protocols such as those introduced by Twitter should soon become the standard for security protection online. He urged other web application developers to consider placing similar protections on their own sites.
"At the end of the day, we are writing this not just to discuss an interesting piece of technology, but to present what we believe should be the new normal for web service owners," he said,
"A year and a half ago, Twitter was first served completely over HTTPS. Since then, it has become clearer and clearer how important that step was to protecting our users’ privacy." ®