10:28 AM

Google Wallet PIN Cracked

Fix for mobile payment vulnerability could require banks to take over some security responsibility.

When researchers late last year revealed that the Google Wallet app stored sensitive user data in plain text locally on the device, they also gave the app credit for its PIN protection. But now that last line of defense has been exposed by another researcher, who this week released a proof-of-concept (PoC) for cracking the Google Wallet PIN.

Joshua Rubin, senior engineer with Zvelo, posted his PoC that demonstrates how he cracked Google Wallet's four-digit PIN, used to authorize and process mobile-phone payments. The PIN is considered the extra layer of security that a plain, old credit card wouldn't have. But Rubin poked a big hole in that strategy: "With this attack, the PIN can be revealed without even a single invalid attempt. This completely negates all of the security of this mobile phone payment system," Rubin said in a blog post.

In December, researchers at viaForensics said they had found that the app locally stores some payment card data in plain text, such as the cardholder's name, transaction dates, email address, and account balance.

Google Wallet lets consumers transact credit-card charges, redeem gift cards, and use loyalty membership cards in stores from their phones. To run the app, the users must type in their four-digit PINs when they launch the app.

While Google Wallet hides the full credit-card account number, the last four digits reside in plain text in the app's local SQLite database, viaForensics found. viaForensics also found that the app repels man-in-the-middle attacks, and at the time gave the app credit for being protected by a PIN to conduct transactions with the cards.

Zvelo's Rubin, who posted details on the PoC as well as a video of it, was able to brute-force the PIN, which was a long-integer "salt" plus a SHA256 hash.

Wallet uses near field communication (NFC), based on RFID technology, and it communicates with a so-called secure element (SE) stored in a chip on the device. "It's like the chip and pin model in European credit cards," says Tyler Shields, a security researcher with Veracode.

Read the rest of this article on Dark Reading.

It's no longer a matter of if you get hacked, but when. In this special retrospective of news coverage, Monitoring Tools And Logs Make All The Difference, Dark Reading takes a look at ways to measure your security posture and the challenges that lie ahead with the emerging threat landscape. (Free registration required.)

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
User Rank: Apprentice
2/14/2012 | 5:25:38 AM
re: Google Wallet PIN Cracked
Google responded to the attack uncovered by the smartphonechamp blog over the weekend by temporarily disabling the provisioning of prepaid cards.
Brian Prince, InformationWeek/Dark Reading Comment Moderator
InformationWeek Elite 100
InformationWeek Elite 100
Our data shows these innovators using digital technology in two key areas: providing better products and cutting costs. Almost half of them expect to introduce a new IT-led product this year, and 46% are using technology to make business processes more efficient.
Register for InformationWeek Newsletters
White Papers
Current Issue
Top IT Trends to Watch in Financial Services
IT pros at banks, investment houses, insurance companies, and other financial services organizations are focused on a range of issues, from peer-to-peer lending to cybersecurity to performance, agility, and compliance. It all matters.
Twitter Feed
InformationWeek Radio
Archived InformationWeek Radio
Join us for a roundup of the top stories on for the week of July 17, 2016. We'll be talking with the editors and correspondents who brought you the top stories of the week to get the "story behind the story."
Sponsored Live Streaming Video
Everything You've Been Told About Mobility Is Wrong
Attend this video symposium with Sean Wisdom, Global Director of Mobility Solutions, and learn about how you can harness powerful new products to mobilize your business potential.