The success of Bitcoin not only prompted numerous other cryptocurrencies, but it also put blockchain in the spotlight for the IT industry. Investors jumped on the bandwagon, companies appointed blockchain managers, and countless studies and pilot projects explored the potential applications. But what remains of the former hype? This article sets out on a surprisingly rocky path in the search for clues about where blockchain is being used today.

A blockchain stores data blocks in a strict sequence. Unlike in a conventional database, these blocks are stored in a chain. In order to detect manipulation, each newly added block contains a checksum of the previous block, while other sophisticated techniques ensure that the entire data chain can be stored in a decentralized or distributed manner.

Blockchain's functionality makes it suitable for accounting: It is tamper-proof and every change can be tracked, like a kind of distributed ledger. Blockchain is also ideal for storing individual tokens that represent passwords, images, or currency units, for example.

For this reason, the financial sector jumped on the blockchain bandwagon. Blockchain is still widely used in finance today, primarily for managing and processing cryptocurrencies. The city of Detroit, Mich., in the US recently made headlines for using blockchain to do this. Starting mid-year in 2025, Detroit will be accepting payments in cryptocurrencies [1], enabling people without bank accounts, in particular, to pay their fees and taxes.

In Germany, IT service provider adesso [2] has collaborated with Frankfurt-based finance technology company SWIAT, using adesso as one of several validators. Independent systems ensure that the blockchain used has not been subsequently modified and that all actions carried out on it comply with predefined rules – in this case with SWIAT's blockchain.

Detroit, adesso, and SWIAT are just three examples from the world of finance. The list of blockchain applications in this area goes on and on. But what about projects outside the financial sector?

Anyone searching the Internet for blockchain solutions will initially find mainly feasibility studies along with a wide range of ideas for potential use cases. The majority of these articles date from around 2019, at blockchain hype's peak. It is from this period that Google still turns up blog posts from large companies raving about blockchain and planning its introduction.

Fresh Fish

Around 2019, the logistics industry was among the first to jump on the blockchain bandwagon. The idea was that it would make it possible to securely track goods, containers, and pallets at any time. Every supermarket customer would then be able to check the blockchain to see which trawler caught the prawns in their delicious prawn cocktail and from which part of the sea. The middlemen in the chain would also always know where their goods were (supply chain management). IBM was looking to empower traceability of fresh food [3] with its Food Trust project (Figure 1).

Figure 1: IBM Food Trust logs the transportation of food.

The idea was that the IBM Food Trust project would also be able to store documents and certificates in the blockchain. Producers and intermediaries would thus simultaneously be able to comply with requirements imposed by governments and environmental organizations. The Food Trust project was used by several large food companies, including Australian vegetable wholesalers Antonello Produce [4].

No Comment

I reached out to IBM to learn more about the current status of the Food Trust project. At the time of writing, I have yet to receive an answer to my request.

Blockchain was a big topic at Deutsche Telekom in 2022 [5], but I also failed to receive a response when I reached out to that company for an update. In 2022, Deutsch Telekom splashed out on the Celo [6], Polkadot [7], and Q [8] blockchain networks through its Telekom Multimedia Messaging Service subsidiary. While Celo and Q focus on financial services, Polkadot attempts to connect different blockchains. In all three projects, Deutsche Telekom provided computing capacity via its Open Telekom Cloud, among other things. How Deutsche Telekom is investing in blockchain today and whether it is still involved in the projects remained unclear due to the lack of a response. However, Telekom MMS [9] now seems to have more or less fully jumped on the AI bandwagon.

Officially Dropped

In 2018, German IT service provider Materna developed a blockchain for the city of Cologne that recorded all processes relating to residents' parking. Both law enforcement officers and citizens were able to ask the blockchain whether a parked car had a parking permit for the parking space currently occupied. If put into use, the solution could have made paper parking permits a thing of the past.

In the same year, Materna presented the Citizen Blockchain Project at the CeBIT trade fair. Citizens were asked to submit data from their air monitoring stations to the blockchain set up by Materna. Materna generated a particulate matter map from the measurement data. The solution rewarded all submissions with tokens. Participants could then use these to make purchases in local stores or an online store. The Citizen Blockchain, which is based on Ethereum, was also geared to support further similar projects. Materna even set up its own blockchain lab for research and implementation.

I contacted the Materna press office to find out what has become of the two projects (information regarding both projects is no longer available on the Materna website [10]), and again there was no response. However, one thing is certain, the city of Cologne continues to issue its legacy resident parking permits, which have to be placed on the windshield.

After all the hype, interest in blockchain seems to have cooled off considerably. With a little patience, however, you can still find blockchain in practical use cases outside the world of finance.