Early users of a mobile payment app called CurrentC may discover their contact information and other information has already been lost to third parties, casting doubt on whether retailers can provide a secure alternative to Apple Pay.

Supported by the Merchants Customer Exchange (MCX), CurrentC was championed by Wal-Mart and other major retailers as a way to bypass the need to use credit cards and let consumers pay with their smartphones. However, Business Insider confirmed that some participants in the beta program have already been informed that their email addresses have been affected by a data breach, though the exact number of those affected was not reported.

As a detailed profile of CurrentC on Re/code noted, the app isn’t expected to be widely available until sometime next year, and it’s uncertain at this point whether the early loss of user data may push things even further. MCX consortium members hope the app proves more popular than Apple Pay because it would mean they wouldn’t incur the same credit card fees.

Though the CurrentC app itself was not hacked, the loss of email addresses may prompt people who are reluctant to adopt Apple Pay to consider other alternatives such as Google Wallet.

A comparative analysis of the two mobile payment systems on Tech Times pointed out that although Google Wallet uses a certain level of token-based security not unlike Apple Pay, it stores it in the cloud, which may make some consumers nervous after the recent high-profile incidents of cloud-based system hacking involving A-list celebrities.

Meanwhile, an editorial on Bloomberg View argued that Apple Pay, CurrentC and any other mobile payment apps could learn from PayPal, which thrived in the early days of e-commerce by helping retailers reduce fraud. That reputation for security may help PayPal in its quest to stay competitive with Apple Pay.

Then there’s Square, the firm co-founded by Twitter’s Jack Dorsey, which has recently opened up a marketplace for developers to create apps that integrate with its own service, according to The Next Web. If security becomes a differentiator for some of those apps, it may help Square look more compelling than Apple Pay, Google Wallet or CurrentC.

Ultimately, any data breach is bad news for all mobile payment providers, experts told Bank Systems & Technology. What it may mean is that consumers become so nervous about hackers that they avoid any new services altogether. The ultimate rival to Apple Pay and the rest could be an old-fashioned wallet full of credit cards.