True, a hissing phone would be really easy to eavesdrop on, but you'd want that transaction data encrypted anyway. And as retro (and annoying) as it would sound at a POS, a pay-by-hiss system would work even for smartphones without a camera and high-resolution screen—all the phone needs is a speaker and microphone. Still, there's that hiss, which certainly would be out of place in a tony store and might be inaudible on Black Friday. But maybe there's a retro solution for both those problems. Acoustic couplers, anyone?
In-store mobile payments are still looking for the right technology, with NFC struggling for a foothold and QR codes only successful in pockets (or, more accurately, in Starbucks). But a new smartphone mobile wallet announced on January 18 by China's Alipay takes a new tack: It communicates via what Alipay describes as "white noise." (We're pretty sure what that really means is "it sounds like the hiss of a dial-up modem, just without all the screeching.") The Alipay wallet isn't currently supporting POS payments, just data transfers between phones. But there's no special reason it couldn't be used for transactions, especially because that's the business Alipay is in.