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There are a number of choices for checkpoints to use with staff attendance tracking smartphone apps, these include NFC, Bluetooth low energy and QR codes. It can be difficult to know which checkpoint is most suitable to use. Information on how each checkpoint works, its good and bad points can make the decision easier.

What are QR Codes?

QR codes are a type of 2-dimensional barcode and work using the same basic principle. Barcodes were invented by Norman Joseph Woodland and Bernard Silver as a way of visualising data in a machine-readable format. They based their idea off morse code. After they patented the barcode in 1951, different types of barcodes were trialled in a variety of scenarios such as for tracking rail cars.

However, a commercially reliable barcode system wasn’t accepted until 1974 when a type of barcode called the Universal Product Code was created and adopted by the retail sector. The first thing that was scanned was a 10 pack of Wrigley’s Juicy Fruit chewing gum. Uses for barcodes have expanding from this time, as has the variety of barcode, including 2-dimensional versions.

The QR code was invented in 1994 by the Japanese automotive company Denso Wave to track components on high-speed assembly lines during the manufacture of vehicles. Originally, QR codes were relatively small but over time the newer versions that have been created are larger, store more information, and can be read more accurately, even with a small fraction of the code missing.

How Do QR Codes Work?

Fundamentally, all barcodes encode some sort of information (usually a number), in the form of a pattern on a surface, for example black and white lines on a piece of paper. However, barcodes have been created in a range of patterns and colours. The barcode pattern is then read and decoded by some sort of purpose-built optical scanner.

QR codes are made of a matrix of black and white squares. Due to the complicated 2-dimensional pattern, QR codes can only be read by a CCD (Charged Coupled Device) such as the digital camera of a smartphone. A software application loaded onto the processor within the phone then digitally analyses the pattern.

First, three distinctive squares at the corners of the QR code image are located, and then a smaller square (or multiple squares) near the fourth corner is used to normalize the image for size, orientation, and angle of viewing. The small dots throughout the QR code are then converted to binary numbers and validated with an error-correcting algorithm. The time taken to read and process the QR code depends on the quality of both the camera and the code.

Although a variety of information can be encoded on a QR code the only information needed for staff attendance tracking systems is a unique ID number.

What Are Some of the Uses for QR Codes?

Apart from automotive industry QR codes have had increasing use in the past two years due to the adoption of the technology for smartphones, particular for COVID-19 contact tracing. Because QR codes can be easily created and printed, QR codes can potentially have a wide variety of used where information can be shared such as marketing in magazines and shop posters. Other uses include ticketing, product tracking, menus, Wi-Fi logins, business cards and payments.

Security and QR Codes

The widespread adoption of QR Codes with smartphones and the ease at which information can be passed from the code to phone has raised issues surrounding security. In particular, the ability of QR codes to automatically connect to a Wi-Fi network or website URL means that criminals can potentially use QR codes for nefarious or malicious purposes. From this the QR code can allow access to various parts of the phone depending on the user’s privacy settings such as,

  • the camera
  • the microphone
  • the GPS
  • full Internet access
  • read browser history
  • passwords
  • transactions
  • read and write contact data
  • read and write local storage such as files
  • global system changes.

The QR code may even give access to the phone privacy settings. This can enable identity theft, the loading of malicious software such as viruses, or make the phone call or SMS predefined number. Such QR codes can be placed over legitimate codes.

QR codes used for payments have a special security feature embedded within the code, where some of the segments must be read by an encryption key.

What’s Good About QR Codes?

Like NFC and passive RFID tags, QR codes require contactless interactions without the need for a battery. However, the main advantage of QR codes is the initial low cost of setting up the system. This is because these systems are promoted as an app that runs on a personal phone owned by the staff members and checkpoints made of stickers that the managers can download and print themselves. Although this system can be cheap to run, it comes with many hidden costs.

Copying QR Codes

The ease at which QR codes can be printed by the business manager also makes it very easy for staff to photograph and print copies of the QR codes. The staff member can then keep copies of these codes on themselves, and scan them at the pre-determined time, regardless of whether they are at the correct location and doing their duties. QR codes make it too easy for staff to get away with not doing their job.

Special QR codes are available that cannot be as easily copied and printed, but these are much more expensive to produce as they need specialist software and equipment, which takes away the only advantage of using QR codes in the first place.

The Readability of QR Codes

Because of the reliance on a camera reading a pattern printed onto a surface, QR codes can have readability issues compared to other types of checkpoints. Various factors can make a QR code difficult to read including the print quality, dirt, damage, surface reflections, scanning angle, and lighting.

To be read, a QR code needs the staff member to not just have their phone set to read the code, but they need to purposefully line up the camera on the phone at a suitable distance from the QR code and hold it in this position until the code is read. Poor readability can add to the time it takes for a phone to read and analyse the QR code. In some cases, the code may not be readable at all.

Checkpoint Durability

Apart from being easily copied, the other big disadvantage of using QR codes is a lack of durability. This is due to the QR code (and its information), being printed on a sticker which can be easily damaged, whereas other types of checkpoints have the chip, with the vital information enclosed in a protective case.

QR codes have been designed to be readable with a small part of the code missing but cannot be read if there is significant damage or key sectors of the code are missing. The most likely parts of a QR code to be damaged are on the outside of the code, these are also the areas with most of the important information.

More durable waterproof vinyl stickers have a plastic surface which are harder to print small, clean, crisp and smudge-proof detailed information. As well, these stickers can reflect light and therefore be harder to read. Placing the QR code behind glass or a plastic coating can also introduce issues with reflected light.

QR Codes and Smartphone Compatibility

Apart from being able to make checkpoints inhouse, the other big appeal of QR codes is that the app can be installed on the staffs’ personal phones, negating the need to purchase specialist hardware. This relies on the assumption that all staff members have QR code compatible phones.

Generally, newer smartphones (that is Android 8 or iOS 11 and higher), will have a QR code reader built into the operating system, but this is not totally guaranteed for cheaper phones. Older devices need to have an external app downloaded onto the phone to be able to read a QR code, and in many cases the app may not work or cause other issues on the phone.

Compatibility problems can be solved by supplying the staff with phones, which will also make it easier to lock the phone for work use only. However, supplying phones will add to the initial set up costs of the system as well as the ongoing costs that come from replacing phones that are much easier to damage than purpose-built hardware.

Summing Up

Yes, the initial cost for using a QR code-based system for staff attendance tracking can be low, but this is offset by long term costs that result from the lack of system usability and reliability. Ultimately, the point of using an electronic tracking system is to prove to your clients that the service has been delivered to the required contractual expectations. This is difficult to prove for a system where the checkpoints are easily damage or copied.

Making copy proof QR codes, and then repeatedly replacing damaged checkpoints adds cost to using the system. Along with frustration. UniGuard has considered offering QR codes but decided against doing so because we value both our reputation, and that of our customers.

If you are looking for a high-quality staff attendance tracking system that meets your needs, contact our sales team today.