Development of a system for secure access data sharing

With ever-increasing digitalization, cybersecurity is becoming one of the most important topics in the field of information technology. Closely related to this is the issue of authenticating users and storing their login credentials. In this context, password management applications have become popular. These tools often provide a function for secure sharing of stored data and usually use hybrid encryption for this purpose. However, this is not effective for sharing data among groups and they do not provide cryptography-based authorization for data access. The main objective of this work is to design and implement a system for secure storage and sharing login credentials at the scale of a minimum viable product (MVP), which will use the latest advances in cryptography. Furthermore, two sub-objectives are set. The first is a survey of current cryptographic tools for confidential data sharing and the second objective is an analysis of current password manager implementations. As part of a sequential research, the Messaging Layer Security (MLS) standard was selected for secure exchange of confidential data between multiple participants. At the same time, an analysis of selected popular password management applications was performed. The obtained knowledge was subsequently used to develop a system according to the MMSP methodology. With its help, a web application consisting of a backend part using the API Platform framework and a frontend part using the TypeScript library React was designed and implemented. The choice of a specific implementation of the MLS standard was crucial. The OpenMLS implementation written in Rust was used. This implementation was extended and integrated into the frontend part of the application. Finally, the application was deployed to a pre-production environment and user tested. The result of this thesis is a functional MVP-scale web application using state-of-the-art cryptographic tools. As a result, the application enables secure and efficient sharing of access credentials, even in large, dynamically changing groups. The resulting application along with all source code is available under an open-source license.