Identity

The design of the identity provider is the first decision for the design of the data space. If a central identity provider is chosen to manage the identities for all participants, every other service depends on this central verification, and decentralized designs are no longer fully feasible.

Which mechanism to use to identify participants is the most fundamental design decision. It impacts policies on autonomy and sovereignty as well as technical solution architectures for other components of a data space.

Identity System	Advantages	Disadvantages
Centralized identity	Simple management for DSGA	Low autonomy and sovereignty of participants
	High degree of control for DSGA	Single point of failure
	Traditional, well-known technology stack	Single point of attack
		Harder to manage for participants
Decentralized identities	Full autonomy and overeignty for participants	Complexity: DSGA management requires decentralized protocols
	Low resourcing need for DSGA	Lower degree of control for DSGA
	Easy to manage for participants	New and partially unfamiliar technology stack
	Harder to attack

Attributes & self-description

Attributes and self-description should always be available as verified presentations. The exact serialization format and service endpoints depend on the implementation of the data space and the trust anchors in use.

Note: The disadvantages listed for decentralized identities describe governance and operational trade-offs, not a loss of participant agency. DSGAs may define accepted trust anchors and onboarding processes; participants remain free to accept or decline those trust anchors and thereby preserve agency in their decision to join or interact.