How does the technology behind QR codes work?

If you’ve recently downloaded train tickets, added a flight ticket to your phone’s digital wallet, or even dined at a restaurant that uses digital menus, the chances are you will have used a QR, or ‘Quick Response’, code. 

What is a QR code?

QR codes are a form of two-dimensional code that have the ability to store data and can be decoded quickly, allowing the user access to a particular service via their smartphone. Every QR code consists of a number of black squares and dots that represent certain pieces of information. This works in  a similar way as a barcode at the supermarket, with each individual item being able to be identified based on the pattern of the code.

How do they work?

There are two ways in which QR codes can be used. The first way is where a business wants the user to scan their QR code in order to access a service. This is usually a web page but can also include a multitude of other media too (e.g. videos, images etc). A restaurant, for example, may ask you to scan a QR code using the camera application on your smartphone to access their menu online. When your smartphone scans this code, it translates that information into a website address, which then automatically presents you with a link to click on and read the menu.  

While you could just type in a web address on your phone to visit the website, the point of a QR code is to simplify the process. 

Apple’s iPhones all have built-in QR code scanning capabilities right in the camera app itself, so there’s no need to download a separate scanning app. By default, if you launch the camera app and point it at the QR code a URL will pop-up. However, if you don’t want the camera always pulling up any QR codes that appear in view, turn the toggle off under Settings → Camera → Scan QR Codes off.

Android phones differ slightly in that if your phone has the Google app, and you don’t need anything more to scan a QR code. Likewise, if you have a Samsung phone with Bixby capabilities, Bixby can also automatically detect QR codes. However, if you own a slightly older model, you may need to download a QR scanner app in the Google Play store to get access to QR scanning capabilities. 

The second way QR codes are used is where a company scans a QR code generated on your phone, for example with tickets for travel or concerts. Once you have the QR image on your phone screen, you simply need to hold it to the QR reader provided by the business to grant you access. 

Are they secure?

QR codes themselves cannot be hacked. However, if you’re scanning a QR code that’s supposed to take you to a legitimate website, how can you be sure that it’s actually taking you to a safe place? Well, in truth, you can’t always. It is therefore important to make sure the business you’re scanning the QR code from is reputable. While QR codes themselves cannot give your phone or device a virus, the link it creates could be one that gives your device malware. 

If you are concerned about getting malware from a QR code, apps exist that can scan the codes and tell you if the site they’re sending you to is safe or not. However, if you remain vigilant about your sources, these aren’t a necessity. 

With this technology on the rise, understanding how it works and how safe it is is paramount to making sure you feel comfortable using it.

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