Risk Assessment Farrokh Alemi, Ph.D. Monday, July 07, 2003

Components of Risk Analysis EPHI boundary definition Threat identification Vulnerability identification Security control analysis Risk likelihood determination Impact analysis Risk determination Security control recommendations Based on Steve Weil’s recommendations

Step 1: EPHI Boundary Definition Inventory of Information system hardware and software details, including: – Internal and external interfaces of information systems – Identification of the primary users of the information systems and EPHI – Basic function and purpose of the EPHI and information system – Technical controls (e.g., hardware or software access control mechanisms, encryption) and non technical controls (e.g., security policies, employee training) being used to protect EPHI and information systems

Step 2: Threat Identification Natural: floods, earthquakes, tornados, etc. Human: unintentional (incorrect data entry or accidental deletion of data) and intentional (denial of service attack, installing malicious software). Environmental: power failures, hazardous material spill, etc.

Step 3: Vulnerability Identification Vulnerability lists such as the NIST vulnerability database ( Trace the “footprint” Defined rules of engagement (what time of day the assessments can occur, what types of attacks are appropriate, what systems will be assessed, etc.) BEFORE the assessment begins

Step 4: Security Control Analysis Access control Authentication Audit trail Alarm

Step 5: Risk Likelihood Determination Three factors should be considered: – Threat motivation and capability – Type of vulnerability – Existence and effectiveness of security controls Numerical rating of risks – Frequency – Subjective probability Divide and conquer Group consensus Estimate-talk-estimate Upper and lower limits

Step 6: Impact Analysis Confidentiality: EPHI is disclosed or accessed in an unauthorized manner Integrity: EPHI is improperly modified Availability: EPHI is unavailable to authorized users

Step 7: Risk Determination Aggregate risks from individual factors to identify risk for a specific system containing EPHI – Under assumptions of independence Bayes formula could be used Posterior odds of security breach is equal to prior odds multiplied by likelihood ratios of each threat

Step 8: Security Control Recommendations Mitigate Eliminate Insure Hedge

Sample surveys Ontario Privacy Diagnostic Tools HIPAA Compliance Gap Identification EDI risk assessment check list