130 likes | 363 Views
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
E N D
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 (http://icat.nist.gov) • 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