The `ECKeyValue` type as described in the [W3C Recommendation for XML-Signature Syntax and Processing](https://www.w3.org/TR/xmldsig-core/#sec-ECKeyValue) is now supported. A new `EC_TYPE` constant has been added to the `javax.xml.crypto.dsig.keyinfo.KeyValue` interface. Please note that only the `NamedCurve` domain parameter type is currently supported, and the `ECParameters` explicit curve parameter type is not supported.