What just happened? Amazon has been slowly rolling out its palm-based biometric authentication system since 2019 and is now preparing the technology's first major expansion across the US. The company claims palms are a more secure biometric identifier than fingerprints or faces, but it remains to be seen whether customers will trust Amazon with any biometric data.

Amazon's contactless biometric payment processor, Amazon One, will be available in all 500-plus Whole Foods stores across the US by the end of 2023. The move initiates the widest public expansion yet for the palm scanner, which the company has tested in a few hundred locations.

Users can sign up for Amazon One either online or at the site of their first purchase using the system, at which point it will scan their palm. Customers can then authenticate purchases by holding their palms over the register. Amazon says the contactless system is easier than paying with NFC through a smartphone or smartwatch.

The company also claims its "palm signatures" are more secure than other biometrics because Amazon One doesn't actually scan the user's palm print. Instead, it creates a numerical, vector image based on the palm and the hand's underlying vein structure, which can't be replicated, then stores it in the AWS cloud. Furthermore, customers must willingly stretch out their palms to activate the scanner, making the process more deliberate than a finger or facial scanner.

Amazon Prime members can use Amazon One to receive savings and other loyalty benefits. Currently participating banks include American Express, Discover, MasterCard, and Visa.

What eventually became Amazon One first emerged in reports and patents in 2019. Since officially announcing the service in 2020, Amazon has slowly introduced it to around 400 locations, including Amazon Go stores, special live events, and over 200 Whole Foods sites in 20 US states. Other businesses like Panera Bread, Coors Field, and Hudson have also utilized Amazon One to some degree.

Another contactless purchasing system Amazon has introduced in a limited capacity is called Just Walk Out, which automatically detects what customers grab and charges them without any interaction with a cash register or store employee. Users authenticate payment methods upon entry and exit, and the technology uses deep learning and multiple sensors to detect what they remove from shelves and automatically place it in their virtual shopping carts.