There is no consensus on an exact definition of self-sovereign identity yet. This paper uses the terminology of SSI, as the concept of individuals or organizations having sole ownership of their digital and analog identities, and control over how their personal data is shared and used. This adds a layer of security and flexibility allowing the identity holder to only reveal the necessary data for any given transaction or interaction. Since identity is such a central part of society, we need to ensure that user control will be the primary foundation SSI will be built upon.
Under self-sovereign identity model, individuals and organizations (holders) who have one or more identifiers (something that enables a subject to be discovered and identified) can present claims relating to those identifiers without having to go through an intermediary. As a result, the best way to implement a system with self-sovereign identity would be through blockchain technology where no intermediary is needed. In order for a system like this to be successful, it needs to adhere to a set of guiding principles, which are outlined in this paper.