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to all the applications on behalf of the user. Consequently, the user only needs to

provide credentials to the FId, allowing him/her to use one account for multiple

roles.

3

Decentralized Identity and Access Management

Decentralizedidentitiesareacorecomponentofthedecentralizedidentifiersstandard

(DID) [19]. Decentralization of IAM as a concept needs to be redesigned from scratch

in order to provide an efficient, more secure solution. The DID standard, while it

is not yet fully developed in order to be globally used, can provide the basis for

creating architectures for decentralized IAM. In this section the basic components

of a decentralized IAM will be presented, while their differences with the traditional

centralized one will be mentioned.

3.1

New Concepts and Components

The centralized architecture models have a number of specific components. While

their functionality remains the same in a decentralized model, the properties of these

components must adapt accordingly.

In Table 1, the basic components of an IAM system are shown, as well as

their counterparts in a decentralized architecture that is based on blockchain. These

components can be divided into three major categories, network, logic and interface,

according to their functionality within the IAM system.

3.1.1

Network: Identity Provider–Identity Issuer–Identity Validator

An identity provider is the component which habilitates the services, both for issuing

a new identity or adding new attributes to existing identities and validating them. In

a decentralized environment, these two functions can be separated and be distributed

across the network running on different kinds of nodes, the identity issuers and the

Table 1 Centralized versus

decentralized IAM

components

Centralized

Decentralized

Network

Identity provider

Identity issuer

Identity validator

Logic

Authorization policies

Smart contracts

Identity

Decentralized identity

Interface

User credentials

Personal wallet

Login interface