Google is disabling its prepaid cards for Google Wallet used in some NFC phones – for now – following the discovery of two hacks that leave users' cash vulnerable.
The first weakness was identified by security firm Zvelo and the second by The Smartphone Champ, both involving the cracking of user PIN numbers, leaving Google Wallet potentially open to money being stolen from consumer accounts.
Users load funds from another credit card in order to use Google Wallet, which then acts as the source for payments made through contactless technology over an NFC-enabled phone.
Customers of Google Wallet will no longer be able to use a Google prepaid card to add money to their account, although they can still use a Citibank MasterCard to do so.
Osama Bedier, vice president for Google Wallet and Payments, wrote on the company blog that clamping down on prepaid cards is a temporary solution.
"To address an issue that could have allowed unauthorized use of an existing prepaid card balance if someone recovered a lost phone without a screen lock, tonight we temporarily disabled provisioning of prepaid cards," Bedier said. "We took this step as a precaution until we issue a permanent fix soon."
Bedier also attempted to reassure users about the security of Google Wallet.
"In fact, Google Wallet offers advantages over the plastic cards and folded wallets in use today ... Google Wallet is protected by a PIN – as well as the phone's lock screen, if a user sets that option."
Google Wallet launched in the US in September 2011.