Doichain – A Blockchain-Based Approach to Double Opt-In

Stephan Zimprich from Fieldfisher and the eco Association began this session with a brief explanation of the characteristics of blockchain that make it interesting for legal reasons: these being that it is a transparent form of documentation, and it is revision-proof, meaning that its history cannot be changed. He then went on to describe Smart Contracts: blockchain-based applications that allow credible transactions without the need for a third party making transactions trackable and the documentation irreversible. Further to this, he introduced the concept of a Daap – a decentralized application which runs on a blockchain. Daaps do not require a provider or hoster. They are open source and can create crypto hash tokens.

Potential value of blockchain for email marketing 

From this point, he turned his attention to email marketing. Sending marketing emails to recipients requires the unambiguous consent of each recipient. This consent can be given in the form of a double opt-in (DOI), however, proof of consent can prove difficult, because it is possible to manipulate log files. The risk exposure for email marketers has increased since the EU General Data Protection Regulation (GDPR) came into effect in May 2018. Zimprich mentioned that recently, a fine of £40,000 was imposed on the UK company Grove Pension Solutions for sending unsolicited mails to around 2,000 recipients. This illustrates the real risk of sending marketing emails without being able to prove that you are entitled to do so.

Before handing over the floor to André Moll, Stephan Zimprich concluded that blockchain allows you to demonstrate that a DOI actually happened – and can do this in a revision-proof manner.


André Moll from Doichain LVC then introduced Doichain, a blockchain-based application for documenting and storing DOIs. Doichain is based in Lichtenstein, which he said was the first country in the world to have blockchain law. Doichain was started in response to the EU General Data Protection Regulation (GDPR) and he hopes it will become a standard for secure email permissions. The application is based on bitcoin technology, because it is the biggest and most-commonly used blockchain.

Doichain documents fraud-proof DOIs, providing proof of existence of the DOI email and registration, including the conditions that were displayed at the time of opting in. It also enables the ISP to check the receiver’s permission in real time, which, Moll pointed out, can help with spam protection. Furthermore, Moll describes it as universal, because everyone has access, it is usable worldwide, the blockchain is permission-free, the source code is freely accessible, and the API is freely accessible and freely usable. 


Potentially Interested parties:

According to André Moll, the developers of Doichain identified four groups of potential interested parties for the application, and their respective benefits. There were:

1. Lead generators – legal certainty and an improved reputation

2. Brand/list owner – no spam traps, legal certainty, higher reputation, and therefore more successful campaigns

3. Email recipients – higher security, higher trust and less spam

4. ISP – no false positives, clear delivery criterion, increased customer satisfaction, differentiation from competitors, and additional revenue (here, he calculated that a large ISP with 20 million inboxes could earn €10 million per year in revenues, in the case of Doichain having a 100% market share – in response to questioning from Stephan Zimprich at the end of the session, he admitted that this would be “in a perfect world”). Implementation for ISPs includes investing in the installation and testing of the node software, and the operation of a server suitable for 20 million inboxes. There are no license fees and no commissions. 

Moll concluded by saying that Doichain currently handles 3,000 transactions per second, but that a second layer is planned that will enable unlimited transactions per second. 

In the subsequent Q&A session with Stephan Zimprich, Moll said that, although there remains a risk in China’s intention to ban Bitcoin, he believes recent rises in the value of Bitcoin is demonstrative of the fact that the blockchain is sound, and he believes that many other countries will keep mining going.

Responding to further questions from Zimprich, he went on to say that Doichain has been prepared since inception to be useable for other opt-in processes, such as for push notifications, and that it will integrate into common mobile operating systems in the future. The focus is not currently on these endeavors, because the team currently consist of only four people. However, his vision is that Doichain will become a movement, with many people cooperating and deciding together as to the future direction of the Doichain initiative.