In decentralized finance nobody knows you are a dog

Identities are an essential aspect of information systems (IS) as they allow users of a digital ecosystem to interact, build trust, and form relationships. Decentralized finance (DeFi) is a digital, blockchain-based ecosystem that has seen tremendous growth in the last years, however, it struggles with current identity implementations. While academics and practitioners have identified numerous implications, a scientific systematization of the role of identities in DeFi and their potentials and challenges is missing. By conducting a multivocal literature review, we rigorously gather the current knowledge and aggregate the different perspectives and concepts to present (I) a comprehensive conceptualization of identities in DeFi, (II) their potentials and challenges, and (III) concepts to manage the tension in between. Thereby, we aim to lay a foundation for future research on identities that increase DeFi's security, efficiency, and adoption while minimizing or eliminating the drawbacks for data privacy and censorship.