#About Resolver

The resolver is a foundational service in the Vidos ecosystem that translates decentralized identifiers (DIDs) into their corresponding DID documents. Operating according to the W3C DID Resolution specification, the resolver functions as a specialized lookup service that retrieves key material and other identity information essential for verification processes.

#Why use a Resolver?

When an application needs to verify a digital signature, credential, or assertion, it first needs access to the public keys associated with the signer's DID. The resolver provides this critical connection, making verification possible.

The Resolver provides seamless access to cryptographic material across different identity systems, it enables the Verifier to verify digital signatures, credentials, and claims with confidence.

#What is a Resolver?

A resolver works as a bridge between identifiers and their cryptographic material. Given a DID as input, the resolver returns a standardized DID Document and associated metadata as output. This resolution capability enables applications to work with decentralized identifiers across various networks, blockchains, and identity systems.

#Resolver Architecture

The resolver in Vidos has two main components that work together to provide resolution services:

1. Resolver Service: The core implementation that handles the DID resolution process according to the W3C specification
2. Resolver Management Service: Enables configuration and management of resolver instances for different needs

Vidos supports creating multiple resolver instances, each with its own configuration, to support different verification requirements within your organization. For detailed steps on creating and managing instances, see the Resolver Instance Management guide.

#Use Cases

The Resolver Service supports various verification scenarios in coordination with the Verifier service:

• Credential verification: Retrieve public keys to verify credential signatures
• Authentication: Access verification material for authenticating users
• Programmatic access: Resolve DIDs via API using API keys
• Authorization: Support fine-grained access control based on DID attributes
• Message encryption: Get encryption keys for secure communication
• Identity linking: Verify connections between different identity systems

By providing a unified interface to diverse identity systems, the Resolver Service simplifies implementation of these use cases in your applications.

#Summary

The resolver is a critical service in the Vidos ecosystem that:

• Retrieves cryptographic material (public keys) needed for verification operations
• Implements the W3C DID Resolution specification for standards compliance
• Supports multiple DID methods through a unified interface
• Provides a consistent response format regardless of the underlying identity system
• Integrates with Verifier and Authorizer services to enable comprehensive trust solutions

By providing a standardized way to retrieve identity information from various decentralized systems, the resolver enables the interoperability and trust needed for decentralized verification workflows. The Resolver also supports DID URL dereferencing for accessing resources linked to DIDs. See the Resolver Configuration Reference for detailed configuration options.