With the hype around Self-Sovereign Identities (SSI), i.e. digital identities that are under full control of the users, a whole plethora of identity providers have emerged. These SSI providers offer products like digital identity wallets, where users can manage their digital identities in a decentralised fashion - on their own as they like: These identities are often referred to as so-called digital credentials, a digitally signed document that certifies specified properties of some identity. To identify a user, Decentralised Identifiers (DIDs) are often used. Moreover, there already exist Web standards for DIDs and digital credentials.
However: The "flavour" of credential (its data model and signature scheme) as well as the employed DID scheme vary between SSI providers. This hampers interoperability across providers and potentially creates a vendor lock-in. Moreover, all providers offer their own SDK (software development kit, to make life easier for implementors), but under the hood they (should) use and adhere to the defined standards.
In this thesis, you will survey existing SSI providers' solutions (such as Jolocom, Dock, MATTR or Sovrin) and investigate hands-on to which extent they adhere to the defined standards and can be used interchangeably.