Support for non-DOM implementations
While the API SHOULD allow non-DOM implementations to be created, it is beyond the scope of the first version to ensure interoperability between implementations other than DOM. Additional standard service provider types MAY be added in the future and necessary API enhancements MAY be considered for a maintenance revision of JSR 105.
Support for a higher-level API
We expect that programmers MAY design high-level APIs which will be built on the JSR 105 API to hide low-level details, address common use-cases or apply profiling constraints. However, it is beyond the scope of the first version to support these requirements. A high-level API MAY be considered for a maintenance release of JSR 105.
Support for user-pluggable algorithms (other than transform and canonicalization algorithms which is supported by the javax.xml.crypto.dsig.TransformService class)
Allowing developers to plug in their own implementations of XML Signature algorithms without requiring them to create a complete JSR 105 implementation seems like a worthy goal but SHALL NOT be REQUIRED for this release of JSR 105. A solution we are investigating for a subsequent release of Java™ SE is to enhance the underlying JCA/JCE to add better support for registering, parsing and processing XML security algorithms, parameters, and key information.