## 3 The SSI-Based Identity Management  
### Basic Concept of SSI  
According to the World Wide Web Consortium (W3C) working group on verifiable claims, users exist apart from services in a self-sovereign identity (SSI) system. SSI is user-centric in comparison to traditional identity management systems [21]. With the advent of the SSI management system, the introduction of a decentralized management system for identity is being considered. Decentralized Identifiers (DIDs) are established as digital identifiers in a W3C working group that is used to enable trust in distributed environments.  
It is used to give an individual rights about his/her private attributes that can be controlled without the bridge via a third party [22]. As SSI requires minimum disclosure in principle, a new format consisting only of information that needs proof is required, which is called a verifiable presentation. By using SSI, claims-based identity using proof eliminates the function for applications to operate authentication tasks, making account management without a centralizing identity management system [23]. In order to achieve the clear mapping of identities representing the same entity with diverse roles maintained in several locations, it is necessary to lower the cost of maintaining identity repositories that need to enforce consistency.  
In general, the IdP has the authority to validate the attribute value and to publish claims on the mapping to certify the user's ownership of the property. User identification, locating user identities in detail, keeping track of user passwords and accounts, and interacting with other IdP systems do not need to fall under the purview of SP. However, external users in a cloud CDM organization can access the network applications of another  
Figure 2: IdM based on a centralized model in the cloud CDM.  
institute using their own identities thanks to privacy-preserving identity with claims [21, 24]. Because companies can construct additional traits as claims upon which to build access control, claim-based identification provides more freedom.  
SSI can be interpreted as an identity that has given itself authority. Its system uses blockchain to look up user's identifier without a centralized IdP. When a user registers his/her identifier in the blockchain, the identifier and its attributes are issued and then stored in his/her wallet. Blockchains can offer neutral gateways for cross-organizational digital workflows in the SSI design [25, 26], reducing the risk of disclosure of private information. It enables the user to have total control over their unique characteristics. Selective submission of the identity information needed for the service is possible through the channel, and it is also possible to demonstrate the veracity of the given information without involving a third party.  
In this paper, we take a look at a repository that enables a ledger where documents can be held fully secretly. This could enable the creation of a blockchain-based decentralized permissioned database. In such a system, the document with private information can only be stored in a personal wallet and managed in a blockchain by the defined processes, including proving and verifying, and not on a central database managed by the regulator. Figure 3 depicts the SSI-based Identity Management in cloud CDM.