Gets the value of the iat (issued at) claim, or null if it's not available. The iat claim specifies a time at which the JWT was issued. This claim can be used to determine the age of the JWT.
Gets the value of the jti (JWT ID) claim, or null if it's not available. The jti claim specifies provides a unique identifier for the JWT. This claim can be used to prevent the JWT from being replayed (allows a token to be used only once).
Gets the value of the nbf (not before time) claim, or null if it's not available. The nbf specifies a time before which the JWT must not be accepted for processing.