Attacks/Breaches
8/7/2013
11:20 AM
50%
50%

Twitter Overhauls Two Factor Authentication System

Take two: Twitter drops SMS for private keys stored on Android or iPhone smartphones, adds previously missing recovery capability.

10 Twitter Power Tips
(click image for larger view)
10 Twitter Power Tips
Twitter unveiled version 2.0 of its home-built two-factor authentication system Tuesday, which the company promised was "more secure" than its previous offering.

Dubbed "login verification," Twitter's new approach eschews sending one-time codes via SMS to a phone. Instead, the second factor is provided via a unique, private key that resides only on a user's Android or iPhone, and which is generated by the Twitter app.

"When you enroll, your phone generates an asymmetric 2048-bit RSA keypair, which stores the private key locally on the device and sends the public key, which Twitter stores as part of your user object in our backend store, to the server," said Twitter security engineer Alex Smolen in a blog post.

If a user enables the feature, whenever someone attempts to log into his Twitter account -- using a valid username and password -- the site then sends a push notification, requesting verification, to the user's smartphone.

[ Who's worth following? Read 10 IT Leaders To Follow On Twitter. ]

"Within your Twitter app, you can then view the outstanding request, which includes several key pieces of information: time, geographical location, browser and the login request's challenge nonce [one-time request ID]," said Smolen. "At that point, you can choose to approve or deny the request. If you approve the request, the client will use its private key to respond by signing the challenge. If the signature is correct, the login request will be marked as verified."

What happens if the smartphone that's been used to generate the private key for a user's Twitter account goes missing? Helpfully, Twitter now offers a one-time-use backup code. "We encourage you to store it somewhere safe," said Smolen, who noted that this code is randomly generated, using an algorithm inspired by S/KEY. In addition, that code is hashed 10,000 times "to make the backup code work without sharing secrets," he said, meaning an attacker shouldn't be able to reverse-engineer the code and recover a password.

Previous
1 of 2
Next
Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Thomas Claburn
50%
50%
Thomas Claburn,
User Rank: Moderator
8/8/2013 | 2:19:03 AM
re: Twitter Overhauls Two Factor Authentication System
Seems like a promising approach.
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Dark Reading Tech Digest, Dec. 19, 2014
Software-defined networking can be a net plus for security. The key: Work with the network team to implement gradually, test as you go, and take the opportunity to overhaul your security strategy.
Flash Poll
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-4467
Published: 2015-01-30
WebKit, as used in Apple iOS before 8.1.3, does not properly determine scrollbar boundaries during the rendering of FRAME elements, which allows remote attackers to spoof the UI via a crafted web site.

CVE-2014-4476
Published: 2015-01-30
WebKit, as used in Apple iOS before 8.1.3; Apple Safari before 6.2.3, 7.x before 7.1.3, and 8.x before 8.0.3; and Apple TV before 7.0.3, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulner...

CVE-2014-4477
Published: 2015-01-30
WebKit, as used in Apple iOS before 8.1.3; Apple Safari before 6.2.3, 7.x before 7.1.3, and 8.x before 8.0.3; and Apple TV before 7.0.3, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulner...

CVE-2014-4479
Published: 2015-01-30
WebKit, as used in Apple iOS before 8.1.3; Apple Safari before 6.2.3, 7.x before 7.1.3, and 8.x before 8.0.3; and Apple TV before 7.0.3, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted web site, a different vulner...

CVE-2014-4480
Published: 2015-01-30
Directory traversal vulnerability in afc in AppleFileConduit in Apple iOS before 8.1.3 and Apple TV before 7.0.3 allows attackers to access unintended filesystem locations by creating a symlink.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
If you’re a security professional, you’ve probably been asked many questions about the December attack on Sony. On Jan. 21 at 1pm eastern, you can join a special, one-hour Dark Reading Radio discussion devoted to the Sony hack and the issues that may arise from it.