Blog Team Design Prototypes Why Continuous Authentication
Concept Research Questions Methodology Findings

Coffee Shop


Continuing the investigation into physical stores and POS experiences, we spent a sprint or two on high volume commodity purchases in grocery stores and fast food restaurants. We kicked off the sprint with an observational study of 15 different cafes around Pittsburgh and interviewed cashiers and managers. We then prototyped a number of different interactions for how a customer could authenticate at the point-of-sale. These methods included saying your name, taping the phone like NFC, typing in a PIN, or using facial recognition with various styles to authenticate at the point-of-sale.

However, we maintained the constraint that the merchant should not have to buy new hardware, and stuck to a tablet at the technology available at the counter. The general finding overall was that credit cards work very well as an identifier and authenticator in stores, and Continuous Authentication will almost certainly be more practical online for a number of years before it makes sense in a physical store.

3 attributes

Business value to Mastercard

We chose high-volume commodity purchases, "top-of-wallet" buys. People have to buy boring things all the time: gas, toilet paper, fast food. And when they do, they use the first card in their wallet without thinking about it. Since a significant portion of Mastercard's revenue is from transaction fees, this is a meaty area for them.

Opportunity for Continuous Authentication (CA) to enhance the Customer Experience

Some of the benefits Continuous Authentication can provide are reduced fraud, potential for higher volume, speed of transaction increase, better UX, increased brand loyalty, etc.

Social friction

As mentioned earlier, we want to have a cohesive experience for both customers that are using a CA system, and 'legacy' customers. Our design should reduce awkwardness, hassle and a sense of division between people, either cashiers and customers, or peer-to-peer.

We began thinking of the experience a regular customer of an establishment has, let's use a bar as an example. Once finished with their food or drink, they turn to the bartender, say "put this on my tab", and leave. The payment is handled by the establishment. It's an elegant and hassle-free experience. Can Continuous Authentication bring that kind of experience to anyone?

Research Questions

  • In a brick-and-mortar store, how can you identify the next customer in queue?
  • What's the preferred step-up experience in a physical store?
  • Can Continuous Authentication work currently without buying new POS hardware?
  • Who can loyalty and pre-order apps (Starbucks) but used with Continuous Authentication?
  • With Continuous Authentication, how can the payment experience disappear without startling customers?


Users were primed on the concept of Continuous Authentication by reading a fake TechCrunch article we provided to them beforehand.

[ link to fake Tech Crunch page ]

Experience Trumps Speed

In physical spaces, Continuous Authentication is not necessarily faster, but it can make the payment experience disappear

1. Onboarding

How does the person get in the system/sign up for the service? (Bank app, Apple Pay, Mastercard app)

2. Enter store

How does the merchant know you are inside the store?

3. Item Order

How is this assigned to your account?

4. Checkout

How does the merchant know your identity to make sure your order is charged to your account?


01.Users share devices and Continuous Authentication systems need to account for that

"The app would be cool with a family account… I give her a maximum [budget], and it's secure. And if it had a receipt, I could monitor my daughter's buys at Starbucks"

02.Users feel secure for different reasons

"I liked PIN and phone tap because it's more like how it works today."

"Phone tap is the most invasive since it might collect a lot of information without my awareness"

03.Falling back to an existing authentication method is comforting to users, and enhances the experience as it reinforces their current mental model

"I liked PIN and phone tap because it's more like how it works today."

04.Mixed reactions to facial data being collected

"Weird to have the store take a photo of me."

"It scares me when I see my face on screen."

05.Merchants will require significant investment in POS technology to make Continuous Authentication in stores a reality

Observational study findings

1. Speed is a priority for merchants

2. Speed is the only/main hindrance during the payment process.

3. Cashiers don't have a preference over cash, cards or apple pay

4. Thinking about what to order takes the longest in the whole checkout process.