Redaction by Multiple Decisions

[Steven Legg <steven.legg@viewds.com>]

On the last TC conference call Hal mentioned using multiple authorization requests
to redact a document. Basically asking for each discrete piece of the document
whether it is visible. This is the obvious way to do it but it is also expensive,
even using the Multiple Decision and Hierarchical Resource profiles.

The redaction solution I sketched out was the result of looking for a faster way
to do redaction. One request determines whether access to the document is permitted
and simultaneously returns the instructions for redacting the document, as
obligations, if access is permitted.

A profile for redaction could talk about both methods.

Mohammad mentioned interest in redaction for health documents so I was wondering
if there might be existing marking schemes and vocabularies for health records that
might feed into some XACML attribute definitions and concrete examples for a
redaction profile. Anything similar in the military sphere would be interesting too.

Regards,
Steven