One Barcode for Everyone and Everything… Including Authentication?

As the traditional linear 1D barcode celebrates its 50th birthday, its days could be numbered now that GS1 – the global body responsible for barcode standards – prepares for the worldwide acceptance of younger, 2D codes in retail outlets by the end of 2027.

In fact, GS1 anticipates a future where products carry just one single, data-rich 2D code, used by consumers, retailers, warehouse operators, manufacturers, law enforcers, regulators – everyone, in fact – to access information tailored to their particular needs.

To this end, GS1 has launched a new standard – GS1 Digital Link – which sees barcodes upgraded from the traditional 1D barcodes with their Global Trade Item Number (GTIN), to 2D barcodes carrying the same GTIN, but accompanied by other identifying numbers, together with a link to a host of web addresses.

But where do product authentication and serialised tax stamps fit into this vision of one barcode for everyone and everything?

Before we address this question, let’s clarify the difference between 1D and 2D barcodes in terms of content and usage, as well as take a closer look at the new GS1 Digital Link standard.

1D barcodes

The most common barcode for retail product labelling is the instantly recognisable UPC (Universal Product Code). This 1D (one-dimensional) code consists of vertical, parallel lines of varying thickness arranged along one axis. The code has appeared on over one billion different products worldwide since its creation 50 years ago.

During that time, the barcode has revolutionised the retail experience by speeding up the checkout process and allowing retailers to identify products and better manage inventory.

The UPC barcode is composed of 12 digits, encoded in a series of vertical lines. The first six digits correspond to the manufacturer’s identification number, the next five represent a specific product type and packaging configuration, and the last one is a check digit.

Another type of 1D barcode, the EAN (European Article Number), was subsequently developed as a superset of the UPC code, with an additional digit that allowed a tenfold increase in the number of possible unique values. The EAN-13 code also indicates the country in which the company selling the product is based (which is not necessarily the same as its country of manufacture).

UPC and EAN codes are types of GTINs which follow GS1 international standards. GS1 is also the only official provider of these codes. While the codes are used to identify products and keep track of inventory levels, they do not contain any pricing information, given that such information is frequently changing. Instead, when a code is scanned at a checkout counter, it triggers the retailer’s point-of-sale system to look up and display the most recent price for that item.

2D barcodes

In this era of big data, the younger, 2D – two-dimensional – barcode has become increasingly relevant as manufacturers face challenging environments in the form of complex supply chains, regulatory traceability requirements, and consumer demands for improved transparency and sustainability.

2D barcodes, such as data matrix, QR codes or PDF417, use patterns of squares, dots, and other shapes to encode data. Because of their structure, they can hold more data than 1D codes (up to 2,000 characters, compared to 20-25 for 1D codes), while still appearing physically smaller. The data is encoded based on both the vertical and horizontal arrangement of the pattern, thus it is read in two dimensions.

2D barcodes do not just contain alphanumeric information, but also images, website addresses, voice messages, and other types of binary data. This means that a lot of information can travel together with an item carrying a 2D barcode, without the user having to connect to a database.

In addition to holding more information, 2D barcodes can be very small, which makes them useful for marking objects that would otherwise be impractical for 1D barcode labels. Thanks to permanent marking technologies such as laser etching, 2D barcodes have been used to track everything from delicate electronic printed circuit boards to surgical instruments.

While 1D barcodes can be scanned with both traditional laser scanners and camera-based imaging scanners, 2D barcodes can only be read with the latter. However, now that the cost of imaging scanners is falling, 2D barcodes are being increasingly used in supply chain and manufacturing applications, allowing operators to encode more product data and more easily scan items on assembly lines.

This is especially true in the electronics, pharmaceutical, and medical equipment industries, where manufacturers are required to provide a large amount of product tracking information on some very small items. That data could be easily encoded on very small 2D barcodes.

Multiple barcodes for multiple uses

These days, we might see a single product carrying a QR code for consumer-facing applications, alongside multiple other data carriers, such as linear barcodes, other 2D codes, and NFC/RFID tags, for use at point-of-sale, or for internal stock control, or supply chain operations management.

However, multiple barcodes jostling for space on a single product are not only confusing for consumers, but can cause scanning issues at point-of-sale. In one development in China, for instance, seven QR codes were counted on one pack. With this in mind, GS1 has put a plan in place to help industry transition to a single, data-rich 2D code, with multiple uses.

What is GS1 Digital Link?

‘Short answer – it’s the internet,’ said Phil Archer, Director of Web Solutions at GS1, when describing GS1 Digital Link. ‘All we are doing is taking a barcode and sticking it on the end of a URL (web address) – it’s that simple.’

GS1 Digital Link is a standardised structure that allows a single 2D barcode to provide point-of-sale functionality and also behave as a consumer-facing web-based URL. While manufacturers and retailers can continue to use their established GS1 codes, GS1 Digital Link will make those codes web-capable and, for the first time, allow them to be used by customers – globally.

How does it work?

GS1 Digital Link can be used with any type of 2D code. The code is embedded with a ‘URI’, which is essentially a website address with a product GTIN added on the end.

Code issuers can also bring further levels of granularity to the code by incorporating additional identifiers within the URI data string. These could include a product’s batch and lot number or, for serialised products, an individual item code.

The URI points to a menu of data source options for different users and applications. So, while different users scan the same barcode, they are directed to completely different web destinations depending on the app used.

For example, a consumer who reads the QR codes in the store can have a completely different experience to a warehouse operator scanning the same code with a third-party app.

The standard allows for the creation of rules for use by apps and scanners to connect to specific user experiences. In essence, this means that apps can be developed to understand the standard and use the data in a barcode to access specific information.

‘It’s a simple but profound change,’ said Archer. ‘It takes us from a simple way of conveying one number (ie. a GTIN), to a Swiss army knife of opportunity’.


At present, several barriers stand in the way of moving over to a single barcode – notably an enormous global retail infrastructure that’s been designed to work with linear barcodes.

‘For a 2D code you need an image-based scanner – but many current POS systems are only equipped to manage linear barcodes,’ said Paul Reid, Head of Standards and Consulting at GS1. ‘This means that a GS1 Digital Link-enabled 2D code can currently do everything, except go ‘beep’ at the checkout – but we are hoping to change that.’ 

The printing industry will also need to evolve to a more digital printing process for encoding supplemental GTIN information. Straightforward applications, such as batch production with minimal GTIN product identifiers, could be accomplished with offline pre-printed labels, or codes incorporated directly into the packaging. In contrast, applications that demand standard GTIN product data alongside on-the-fly serialised codes or variable production data will require inline printing.

Despite these challenges, a report from GS1 US revealed that 82% of retailers and 92% of brand owners support transitioning from a linear barcode to a 2D code by 2027. That said, it’s unlikely that there’ll be a synchronised ‘switch’ from linear to 2D any time soon.

‘We can’t say exactly when this will be,’ said Reid. ‘For now, the GS1 Digital Link standard will provide the majority of brands with an option for one 2D code, alongside a linear barcode – which is a significant step forward.’

GS1 Digital Link as a tool for authentication?

Now we come to the question of whether the GS1 Digital Link standard can provide a structure for a robust anti-counterfeiting tool. Can the vision of ‘one code for everyone and everything’ also apply to product authentication and tax stamp programmes?

In our opinion, the short answer is ‘no’. At least not unless that code has been reinforced with physical security features such as taggants and optical effects – in the same way that many brands and government authorities are combining the physical security of labels and tax stamps with serialised 2D codes.

While GS1 Digital Link has the potential to enhance product track and trace solutions – in its capacity as an open standard that promotes interoperability on a global scale and across multiple markets – let’s not forget that track and trace does not equal authentication.

This is because a unique identifier for track and trace, without any physical security features, can often be easily copied, to the extent that it looks just like – and ostensibly performs the same function as – a genuine code. Which means it is virtually impossible to know which is the real thing and which is fake, just by comparing two codes side by side.

Another aspect to consider is that the creation of barcodes is essentially in the hands of the brand owner, and that the codes are not necessarily produced in a high-security environment. While manufacturer ID numbers are issued by GS1 member organisations, it is the manufacturers themselves who generate product GTINs based on those IDs, and it is subsequently commercial label printers or packaging companies that print the corresponding barcodes.

So, not a very conducive environment for creating features for product authentication.

However, what is clear, is that GS1 Digital Link is a highly significant initiative, which may prove to be as revolutionary as the UPC barcode.

Therefore, one could ask whether authentication providers will eventually need to re-invent their products in line with this initiative, as well as in light of the fact that how we interact with products is changing. For instance, will security labels and tax stamps still need to carry their own barcode, or would they be able to link up with GS1 Digital Link and drop their own code?

Maybe they could, but as far as product authentication is concerned, we believe that an ‘analogue’ system will still need to be maintained in parallel with the digital world for a very long time to come.