QR code (quick response code) is a matrix code that store huge volume of information and it’s scannable (decrypted at high speed). QR code could be easily misused because user don’t know which information or link hidden until scan. In last a few years QR code became popular because of wider usage of smartphones. But the golden time for QR code started since the World Health Organization declared COVID-19 as a pandemic and encouraged people do not touch surfaces (QR code is touchless).

QR code is a two-dimensional code that was developed by Denso Wave (the Toyota subsidiary) for tracking automobile components throughout manufacturing. Before the QR code, barcode was used but it contained not sufficient volume of information. The barcode storage capacity is up to 20 numerical digits. Barcode is 1D and QR code is 2D. QR code storage capacity is 4,296 alphanumeric characters, 7,089 numeric characters, 1,817 kanji characters (logographic writing system) of information.

Step by step guide on how to make your own QR code

QR code could be made in other colors than black and while but readability of it will be reduced. For QR code could be added different colors (even gradient), design, logo, frame, etc.

QR code system elements (encoder and decoder)

The QR code system consists of a QR code encoder and decoder. But the best feature of QR code that it could be scanned from different angles. To QR code scanners added Reed-Solomon error correction feature (error correction codes are hidden and most users do not even know about them, nor when they are used). The data on QR code structured in that way that way that software can “guess” the missing or misinterpreted pieces. In example of QR code above available code made out of dots. That’s type of QR code could lead to troubles while scan. In regular QR code is used masking process to include misleading shapes (such as dots or hearts), large blank areas, etc. When QR code created, the encoder check different masks and choose that one that minimizes misleading features in the result. The timing pattern contain alternative light and dark modules. In QR code used a few different encoding schemes to ensure that different type of information can be stored efficiently.

How QR code is used to scam you?

The most widely used QR code could include suspicious link and to prevent it available safe QR code scheme based on visual cryptography. Most of users know that QR code can open a URL but it also can compromise email or affect computer. Sometimes scammers place QR code sticker on top of the real sticker. When customer scan the QR code, it can take to spoofed login page to steal users credentials.

First corrupted QR code was detected in 2011 by the Kaspersky Lab. Ones the user scan the code it contained a website link that after clicking on it downloads the malicious file within the user’s device without the knowledge of the user.

Ways to make QR code safer to use

In order to make the QR code authentication more reliable and safe to use, researchers proposed a few ways for authentication. On of the most effective strategy is to use OTP (one time password) and EVC (extended visual cryptography). User’s information could be protected using visual encryption technology (visual information to be encrypted in such a way that the description can be done without any scanner). The main idea is to encode a secret image into noise like shadow images (named share images). The secret image is divided into a few share images and distributed to different participants. The decryption done by stacking a few shared images to reveale the secret image without use of scanner. In this method available weak point: the secret image will be invisible if the number of stacked shared images in not sufficient.

The improved visual encryption technology is based on the existing visual encryption technology. The original secret image is QR code image and two shared images are generated (pseudo random matrix with visual cryptography algorithm).

QR code structure

1. The Finder Pattern situated in three corners of the QR code (only bottom right corner without the finder pattern). Each pattern is based on a black module matrix (3×3) encircled by white modules. The finder pattern identify the exact orientation of the QR code.
2. Separators. Each white separator width=1px and used for recognition boosting for the finder pattern. Separators isolate the finder patterns from the actual data.
3. Timing Pattern. The alternative black and white modules allows the decoder to determine a single module’s width.
4. Alignment Patterns. If QR code deformed, the alignment patterns allows the decoder to process without throwing error. For complex QR codes more alignment patterns added.
5. The Format Information Section. This section is made up of 15 bits next to the separator. It’s used to store error correction rate and masking model selected.
6. Data. Each QR code data is converted into a bit stream and then stored inside the information segment in 8 bit section.
7. Error Correction. Error correction code is stored in 8 bit long code words.
8. Reminder Bits. This section consist of empty bits.
9. Quiet Zone. Each QR code must be encircled by identical color shade as white modules.

Top 10 ways to use QR code for business growth

QR code could be used in many industries. Here’s top 10 ways to use your QR code for business growth:

1. Contactless payments. Governments around the world encourage citizens to use touchless payments to prevent the spread of COVID-19.
2. Business information. QR code connects to most recent business information available on your website.
3. Restaurant menu or business product / service brochure. This reduced need for face to face interaction in restaurants. Restaurant guest scan QR code and redirected to menu, after add selected items to the cart and place digital order.
4. QR code for online reservation. Most of businesses work on appointment only schedule because of COVID-19 pandemic and customers prefer to register by themselves online than to call and schedule the appointment.
5. Online shopping. QR code for merchandise tracking and checking the availability.
6. QR code can capture customer’s data (email and answer on simple question “How did you get to know about us?”) but it couldn’t capture private customer’s data.
7. Qr code for chat with company’s bot. Most of customers prefer to chat than to talk.
8. Qr code for social media links. If you business is not available in social media than you loose potential customers. On average millennials spend two hours per day in social media.
9. QR code on discount offers and giveaways. Make your customers believe that they save money while shopping on your website (use services) and users will be more than happy to spend their money.
10. In supermarkets, libraries, museums and exhibitions. Technically in places where’s huge volume of inventory.

Artificial intelligence algorithms for better QR code recognition

With progress of artificial intelligence algorithms became possible to improve adaptive median filter algorithm & distortion correction method based on backpropagation neutral networks. By using artificial intelligence algorithm, QR code images fitted into the geometric deformation pattern that correct the distortion. For QR code reading predominantly used phone camera that cause uneven illumination and image distortion. The QR code recognition process: image acquisition, image processing, barcode detection, information sampling, information error correction, information decoding and final output results.

Dynamic QR code vs Static QR code

In QR code available two categories: static QR code and dynamic QR code. Dynamic QR code could be edited and shared easily, static QR code could not be changed because data is encoded directly into the code. Dynamic QR code could be used for target URL and could be edited in any time without the need to reprint QR code. Only dynamic QR code could be be active or deactivated by owner.

QR code became the essential part of daily life. This article provided you with all necessary information to understand how QR code works, pros and cons, application.