DecentID: Decentralized and Privacy-preserving Identity Storage System using Smart Contracts

Many Internet services require the registration of an account before permitting use of their services. Over time, many Internet users end up with a multitude of accounts with separated identities. A solution to this problem is offered by single-sign-on (SSO) providers, where a user can create a single identity and use this identity for multiple services. However it requires the user to trust the SSO provider. When the provider blocks access to the identities the users lose access to their subscribed services. To avoid this problem, we propose DecentID, a completely decentralized identity storage system that does not require a centralized trusted third party. Instead, a public blockchain is used as trust anchor. Identities can be created and used for different services. Each service can only read the identity attributes disclosed for it without being able to read attributes the user wants to keep secret.