Computer Security Techniques for Nuclear Facilities : Technical Guidence.

Intro
1. INTRODUCTION
Background
Objective
Scope
Structure
2. Basic Concepts and Relationships
Nuclear security and computer security
Facility functions, computer security levels and computer security zones
Computer security risk management
Competing demands of simplicity, efficiency and computer security
Conceptual nuclear facility zone model
Computer security measures
Computer based systems and digital assets (including SDAs)
Cyber-attack
Interface with safety
3. General Considerations for Computer Security
Identification of facility functions
Protection of sensitive information and digital assets
Risk informed approach
Risk assessment and management
Computer security levels based on a graded approach
4. Facility Computer Security Risk Management
Objective of facility computer security risk management
Outline of facility computer security risk management
Inputs to facility computer security risk management
Phases of facility computer security risk management
Scope definition
Facility characterization
Identification of facility functions
Intrinsic significance of facility functions
Potential effects of compromise of a system on facility function
Interdependencies between facility functions
Necessary timeliness and accuracy for facility function interdependencies
Target identification
Documentation of facility functions
Threat characterization
Sources of threat information
Facility specific threat characterization
Additional considerations for insider threats
Specification of computer security requirements
Computer security policy and computer security programme
Assignment of systems performing facility functions to computer security levels
Defensive computer security architecture specification.

Requirements in the DCSA specification to apply a graded approach
Requirements in the DCSA specification to apply defence in depth
Trust model
Relationship with system computer security risk management - performed for each system
Assurance activities
Evaluation
Verification
Validation
Scenario identification and development
Facility computer security risk management output
5. System Computer Security Risk Management
General considerations
Overview
System computer security risk management process
Overall defensive computer security architecture requirements for computer security
Definition of system boundaries
Definition and construction of computer security zones
Identification of digital assets
System computer security architecture, including digital asset analysis
Verification of the system computer security risk assessment
System computer security risk management report
6. Facility and System Computer Security Risk Management Considerations During Specific Stages in the Lifetime of a Facility
Planning
Siting
Design
Construction
Commissioning
Operations
Maintenance
Cessation of operations
Decommissioning
7. Elements of the computer security programme
Computer security requirements
Computer security policy
Computer security programme
Elements of the computer security programme
Organizational roles and responsibilities
Management system
Computer security indicators
Security design and management
Computer security requirements
Digital asset management
Configuration management
Security procedures
Personnel management
8. Example defensive computer security architecture and computer security measures
Example implementation of defensive computer security architecture
Decoupling computer security zones.

External connectivity
Example requirements
Unassigned digital assets
Generic requirements
Security level 1 requirements
Security level 2 requirements
Security level 3 requirements
Security level 4 requirements
Security level 5 requirements
Appendix SELECTED ELEMENTS OF A COMPUTER SECURITY PROGRAMME
REFERENCES
Annex I POTENTIAL ATTACK SCENARIOS AGAINST SYSTEMS IN NUCLEAR FACILITIES
Annex II EXAMPLE OF COMPUTER SECURITY LEVEL ASSIGNMENT FOR A NUCLEAR POWER PLANT
Annex III EXAMPLE OF APPLICATION OF COMPUTER SECURITY LEVELS AND ZONES
GLOSSARY.