An architectural framework for enabling secure decentralized P2P messaging using DIDComm and Bluetooth Low Energy

Self-sovereign identity (SSI) is an emerging concept that shifts the control of identity to the person or entity to whom it belongs to without the need to rely on any centralized administrative authority. Within the SSI model, a digital identity wallet enables a user to establish relationships and interact with third parties in a secure and trusted manner. However, in order to perform various operations such as messaging and credential exchange, these usually require internet access. In some situations, this is not possible, and entities should be able to communicate independently of any external infrastructure in an offline setting. The objective of this paper is to design a proof-of-concept that would allow for secure, trustworthy, and privacy-preserving decentralized peer-to-peer communication without the need for any external networking infrastructure. For this, we investigate a particular case involving DIDComm and Bluetooth LE. We identify requirements for the architecture and propose an architectural framework that allows two entities to securely communicate. To show our concept's feasibility, we evaluate the existing technologies that could be used in the proposed architecture. Our findings indicate that this approach has the potential to enable a wide range of interesting use cases and can be integrated into existing digital identity wallet solutions to extend the capabilities of offline messaging in a secure and decentralized manner that goes beyond the current models that often rely on Internet connectivity.