> For the complete documentation index, see [llms.txt](https://dev.ishare.eu/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.ishare.eu/version-2.1.1/introduction/specific-technical-standards/json-web-token-jwt.md).

# JSON Web Token (JWT)

A JSON Web Token (JWT) is used when non-repudiation between parties is required. A statement, of which the data is encoded in JSON, is digitally signed to protect the authenticity and integrity of the statement.

iSHARE uses signed JWTs in the following ways:

1. In a request for an OAuth Access Token or an OpenID Connect ID token the client sends a signed JWT. The client is authenticated based on the verification of the JWT's signature.
2. Delegation evidence is presented as a signed JWT. The signature of the Authorization Registry or Entitled Party provides proof to other parties.
3. In a response from a server iSHARE metadata is presented as a signed JWT. The signature is used to bind the iSHARE metadata (such as license information) in the JWT to the content of the response.
4. A service from an iSHARE Service Provider MAY require a request to be signed.

On [this page](/version-2.1.1/reference/ishare-jwt.md) the generic requirements for a signed iSHARE JWT are specified.