Herr XY, geboren am XX in XX, war in der Zeit vom 01.01.2020 bis zum 31.12.2022 als XX in unserem Unternehmen in Gelsenkirchen tätig. Die TrustCerts GmbH ist ein junges Cyber-Security-Unternehmen, welches sich aus dem Institut für Internet-Sicherheit an der Westfälischen Hochschule in Gelsenkirchen herausgegründet hat. TrustCerts entwickelt und erforscht Softwarelösungen, die es ermöglichen, digitale als auch ausgedruckte Dokumente dezentral, unabhängig und unveränderbar über die innovative Blockchain-Technologie auf Echtheit und Gültigkeit überprüfen. Herr XX hatte im Rahmen seiner Tätigkeit umfassend Gelegenheit, Einblicke in die IT-technischen Hintergründe unserer Authentifizierungslösung zu erlangen. Sein Aufgabenbereich umfasste folgende Tätigkeiten: Erforschung und Implementierung möglicher Anwendungsfälle im Themenkomplex Self-Sovereign Identity (SSI), insbesondere von digitalen Nachweisen in Form des Verifiable Credential (VC) Data Models gemäß der W3C-Spezifikation sowie AnonCreds und Mobile Driver's License (mDL)

Summary The peer-to-peer protocol describes how nodes connect to other nodes. It also defines how new nodes are added to the network or existing nodes are removed from the network. Motivation The blockchain network consists of multiple nodes that communicate with each other. We need to establish a procedure for how the nodes initially connect to each other and how new nodes can be added or existing nodes can be removed once the network is established, and to ensure that all nodes have a consistent view of the network. Network-Betrieb Validator connecting to another validator In order to connect to the network, a new validator initially has to connect to one single validator. Once this initial connection is established, the validator sends the new validator the necessary information to connect to the rest of the network.

Summary The consensus algorithm is the algorithm that describes how the consensus is formed about what content will be included in the blockchain. Here, all participating nodes have equal rights. There are various consensus algorithms. We use the TBFT (Trusted Byzantine Fault Tolerance), which is very similar to the very well-known PBFT (Practical Byzantine Fault Tolerance), but generates less overhead. This is described in the following chapter. Motivation Distributed systems and distributed computing require a common understanding and coordinating of a variety of processes and data value that are resistant to tampering and have a fault tolerance. Without it, all network participants lack trust and integrity of data, so it is necessary to agree on a consensus for data processing. One advantage of distributed ledger technology (DLT) like blockchain is the consensus algorithm. The consensus algorithm allows nodes to agree on the integrity and uniform processing of data on the blockchain, creating a common level of trust among all equal network participants. Introduction