Encrypted external non-XML data

Hi,

Something that I would be interested in is the ability to
provide encryption information about an external non-XML
entity:

<EncryptedData xmlns="&xmlenc;"
  Location="foo"
  EncryptionInfo="#encryptionInfo23" />

The rationale is that XML is being used in some situations
to encode control information describing accompanying non
XML data.

Support in this document would allow the control data to
express encryption information in a standard manner, and
the keying information could also be shared with encrypted
nodes within the control document.

Embedding external data within base 64 nodes is not always
practical or efficient.

Merlin