|Abstract||Depending on availability and route characteristics, different modes of transport, e.g., trains, car sharing, public transport, eScooters or bike rental, can be combined to optimize the travel experience. While the benefits of such multimodal trips are obvious to improve travel versatility and comfort, the execution is cumbersome and complicated for travelers and thus typically not utilized. For each service provider the traveler needs to register with similar personal data and create a separate account with username and password to remember. Moreover, the booking and authentication process is different for each service provider and booked tickets may be spread among different applications.
To overcome these drawbacks, we propose a Single Sign-On (SSO) frame work for service providers in the mobility domain, that allows secure data
sharing through an eWallet to simplify multimodal journeys for travelers. Based on a typical multimodal journey use case, we define requirements as well as the system model and specify the corresponding protocols. We implemented a prototype for evaluation and show that our system meets our defined functional and security requirements. Additionally, we show that our system reduces user interactions by at least 51.9% for simple and even more for complex scenarios.|