Father Smith is the director of the Chapliancy Research Program at the VA hospital in Washington, D. C. His article dissects the nature of the word "secret" and outlines the obligations attached to the different kinds of secrets.
Smith, Walter J.
"Some Problems of Confidentiality and How They May Be Avoided,"
The Linacre Quarterly:
3, Article 12.
Available at: http://epublications.marquette.edu/lnq/vol41/iss3/12