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Do I have full control over my identity?

This is the first article about Self-Sovereign Identity (SSI) on our blog. We give an introduction to the topic and present a project that is already well advanced.

Digitization changes us

The pandemic is driving digitization in Germany. Larger companies are investing more in digitization, older citizens are more open to digitization, and home offices have become the norm for many people. Digitization is changing our everyday lives. It connects people who would otherwise have to be physically separated. Above all, however, it ensures that we move around more on the Internet - whether by smartphone, tablet or computer. The traces we leave behind on the web as individuals are becoming ever more numerous. We communicate via WhatsApp, enroll digitally at universities, have a dozen apps for application purposes ranging from hobbies like cooking or running to sleeping at night. We have developed a digital identity on top of our real identity.

From analog to digital identity

My name is Robert, I'm 26 years old and I write professionally for TrustCerts around the topics of blockchain, identity and startups. In the real world, my identity is composed of physical features like my face or fingerprint and personal data like my name, place of residence and date of birth. In the digital world, I usually use a combination of username and password to identify myself to various services. Each of the 110 or so accounts I'm registered with somewhere on the web is linked to me. Not always with the same user name or the same passwords, nor is personal data such as my place of residence or even my account number relevant for all services. And yet they contribute to my digital fingerprint, my digital identity.

If I want to buy a book on the Internet, i.e. carry out a digital transaction, I have to identify and authorize myself to the seller. Either I register directly with the seller in the store or, which is usually more convenient and faster, I use the data I have already stored on Facebook or Google. If I want to open an account online, things get even more complicated. For additional security, I have to digitize an analog document and photograph my ID card. I also film my face from different perspectives in a video ID app.

Using a digital identity app in which I, as a user, can collect and manage certain characteristics and confirmed proofs would make it easier for me to move around the web and at the same time give me an overview of which service I shared which characteristic with at which time. My ID card, verified by the Bundesdruckerei, my account data, verified by my bank, and my credentials, verified by schools and universities would all be in this one app. I could autonomously decide what I want to share with which portal, which body, and also easily revoke these rights again when they are no longer needed. This is data that makes up me and my identity. That's why I think it's only fair that I also manage this data and can decide who receives it.

The identity card on the smartphone

This desired idea of a user-centric digital application to manage one's own identity is currently being implemented under the name "Self-Sovereign Identity" and so-called "Wallets". The basic idea behind this is simple: I, as Robert, 26 and author for TrustCerts, receive all proof and information about myself from trustworthy organizations and institutions. In addition to the analog ID card, I also receive a digital one in my digital wallet and can henceforth identify myself in the digital world without any doubt as Robert, 26. This ID card, also called a "Verifiable Credential," is not relevant in the aggregate for all portals with which I register. If a mail order merchant needs my name and date of birth, I release this information to them. All other data remains obscured for the merchant, as it is irrelevant for him.

This explains a basic principle of SSI: full control over one's own identity. In this case, the Bundesdruckerei is the issuer of the Verifiable Credential "identity card". I, as Robert, 26, am the holder and hold the attributes, such as date and place of birth, in my Digital Wallet. The verifier, the mail order company, can in turn verify the attributes I have released and identify the issuer, which is the Bundesdruckerei. The advantage of this process is that I, as the holder of my identity attributes, have complete control over my identity and the verifier can prove beyond doubt whether the attributes provided are genuine.

The operation of SSI illustrated.

Example: The Lissi app

Lissi is a research initiative whose goal is to create an ecosystem for self-determined identities in Germany and the EU. The project is led by Main Incubator GmbH and supported by many well-known companies and institutions such as Bundesdruckerei and Deutsche Bank.

The management of personal data via smartphone application (Wallet) is the focus of Lissi. The Lissi Wallet simplifies the management of certificates, attestations and personal data. We recommend that anyone interested in SSI technology download the demo for the Lissi app. There, various use cases are simulated. For example, the receipt of an online ID from the Citizen's Office, the attributes of which become important in the further course of the demo in order to apply for a credit card at a bank. We at TrustCerts were surprised at how intuitively this works and are already very much looking forward to using the app and the technology in real life.

The Lissi wallet app. (Copyright:

What about the security of decentralized identities? What are decentralized identifiers and how do they work? What role does blockchain play in the topic of self-determined identities? We will clarify all these questions and go deeper into the topic in our next article. Do you have any questions or suggestions on the topic? Write us an email or via the known channels like Twitter or Facebook.

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