Report Number: CESG/TR/2011/1 Issue: 1.1 Dated: 07/04/2011 Page 1 High Integrity Systems Engineering Group Security Assurance Cases: Motivation and the State of the Art Report Number : CESG/TR/2011/1 Authors : Rob Alexander, Richard Hawkins, Tim Kelly Issue : 1.1 Date : 7 April 2011 High Integrity Systems Engineering Department of Computer Science University of York Deramore Lane York YO10 5GH The information contained in this document is proprietary to The University of York and CESG. It is made available by The University of York and CESG on the condition that, except as provided for by the terms of the contract under which it is supplied, it shall not be copied in whole or in part or otherwise reproduced (whether by photographic, reprographic or any other method) and the contents thereof shall not be divulged to any person other than the addressee without the express prior consent of The University of York and CESG.