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This lecture provides an overview of cyber security modules including risk and governance, security architectures, access control, cryptography, network security, digital forensics, and data management. It also discusses the concepts of confidentiality, integrity, and availability in cyber security.
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Introduction to Cyber Security August 28, 2015 Lecture #2 Dr. Bhavani Thuraisingham
Outline Cyber Security Modules Risk and Governance Security Architectures Access Control Cryptography Network Security Digital Forensics Data Management Security
C. I.A. Confidentiality: Preventing from unauthorized disclosure Integrity: Preventing from unauthorized modification Availability: Preventing denial of service
Ten Major Modules of Cyber Security Information Security and Risk Management Access Control Security Architecture and Design Cryptography Network Security Applications Security (aka Data and Applications Security) Legal Regulations, Compliance and Investigations (aka Digital Forensics) Physical and Environmental Security Business Continuity Planning Operations Security
Information Security and Risk Management Security Management Security Administration Organizational Security Model Information Risk Management Risk Analysis Policies, Standards, Guidelines, Procedures Information Classification Layers of Responsibility Security Awareness Training
Access Control Security Principles Identification, Authentication, Authorization, Accountability Access Control Models Access Control techniques Access Control Administration Access Control Methods Access Control Types Accountability Access Control practices Access Control Monitoring Threats to Access Control
Security Architecture and Design Computer Architecture Systems Architecture Security Models Security Modes of Operation Systems Evaluation Methods Open vs. Closed Systems Enterprise Architecture Security Threats
Physical and Environmental Security What is Physical Security Planning Process Protecting assets Internal Support Systems Perimeter Security Other aspects
Telecommunications and Network Security Open Systems Interconnection Reference Model TCP/IP Types of Transmission LAN Networking Routing Protocols Networking Devices Networking services and protocols Intranets and Extranets Metropolitan Area networks Remote access Wireless technologies Rootkits
Cryptography History, Definitions and Concepts Types of Ciphers Methods of Encryption Type of Asymmetric Systems Message Integrity PKI Key Management Link / End-to-end Encryption Email standards Internet security Attacks
Legal Regulation and Compliance Investigation Cyber law and Cyber crime Intellectual property law Privacy Liability and Ramifications Digital Forensics and Investigations Ethics
Applications Security Database Security Software and applications security issues Secure systems development Application development and security Object-oriented systems and security Distributed computing and security Expert systems and security Web security Mobile code Patch management
Business Continuity Data Storage and Recovery Storage Area Networks Business Continuity Planning Disaster Planning
Operations Security Role of the Operations Department Administrative Management Assurance Levels Configuration management Media Controls Data Leakage Network and Resource Availability Mainframes Email Security Vulnerability testing
Information Governance and Risk Management Security Management, Administration and Governance Policies, Standards, Guidelines, Procedures Information Classification Roles and Responsibilities Risk Management and Analysis Best Practices
Security Management, Administration and Governance Information security (ISec) describes activities that relate to the protection of information and information infrastructure assets against the risks of loss, misuse, disclosure or damage. Information security management (ISM) describes controls that an organization needs to implement to ensure that it is sensibly managing these risks. The risks to these assets can be calculated by analysis of the following issues: Threats to your assets. These are unwanted events that could cause the deliberate or accidental loss, damage or misuse of the assets Vulnerabilities. How susceptible your assets are to attack Impact. The magnitude of the potential loss or the seriousness of the event.
Security Management, Administration and Governance Standards that are available to assist organizations implement the appropriate programs and controls to mitigate these risks are for example BS7799/ISO 17799, Information Technology Infrastructure Library and COBIT. Information Security Governance, Information Security Governance or ISG, is a subset discipline of Corporate Governance focused on information Security systems and their performance and risk management. Establish and maintain a framework to provide assurance that information security strategies are aligned with business objectives and consistent with applicable laws and regulations
Security Management, Administration and Governance Develop the information security strategy in support of business strategy and direction. Obtain senior management commitment and support Ensure that definitions of roles and responsibilities throughout the enterprise include information security governance activities. Establish reporting and communication channels that support information security governance activities. Identify current and potential legal and regulatory issues affecting information security and assess their impact on the enterprise. Establish and maintain information security policies that support business goals and objectives. Ensure the development of procedures and guidelines that support information security policies. Develop business case for information security program investments.
Policies, Standards, Guidelines and Procedures Policies are the top tier of formalized security documents. These high-level documents offer a general statement about the organization’s assets and what level of protection they should have. Well-written policies should spell out who’s responsible for security, what needs to be protected, and what is an acceptable level of risk.. Standards are much more specific than policies. Standards are tactical documents because they lay out specific steps or processes required to meet a certain requirement. As an example, a standard might set a mandatory requirement that all email communication be encrypted. So although it does specify a certain standard, it doesn’t spell out how it is to be done. That is left for the procedure.
Policies, Standards, Guidelines and Procedures A baseline is a minimum level of security that a system, network, or device must adhere to. Baselines are usually mapped to industry standards. As an example, an organization might specify that all computer systems comply with a minimum Trusted Computer System Evaluation Criteria (TCSEC) C2 standard. A guideline points to a statement in a policy or procedure by which to determine a course of action. It’s a recommendation or suggestion of how things should be done. It is meant to be flexible so it can be customized for individual situations. A procedure is the most specific of security documents. A procedure is a detailed, in-depth, step-by-step document that details exactly what is to be done. A security model is a scheme for specifying and enforcing security policies. Examples include: Bell and LaPadula, Biba, Access control lists
Information Classification • It is essential to classify information according to its actual value and level of sensitivity in order to deploy the appropriate level of security. • A system of classification should ideally be: • simple to understand and to administer • effective in order to determine the level of protection the information is given. • applied uniformly throughout the whole organization (note: when in any doubt, the higher, more secure classification should be employed).
Information Classification With the exception of information that is already in the public domain, information should not be divulged to anyone who is not authorized to access it or is not specifically authorized by the information owner. Violations of the Information Classification Policy should result in disciplinary proceedings against the individual. Number of information classification levels in an organization should be a manageable number as having too many makes maintenance and compliance difficult.
Information Classification Top Secret: Highly sensitive internal documents and data. For example, impending mergers or acquisitions, investment strategies, plans or designs that could seriously damage the organization if lost or made public. Information classified as Top Secret has very restricted distribution indeed, and must be protected at all times. Security at this level is the highest possible. Highly Confidential: Information which is considered critical to the organization’s ongoing operations and could seriously impede or disrupt them if made shared internally or made public. Such information includes accounting information, business plans, sensitive information of customers of banks (etc), patients' medical records, and similar highly sensitive data. Such information should not be copied or removed from the organization’s operational control without specific authority. Security should be very high.
Information Classification Proprietary: Procedures, project plans, operational work routines, designs and specifications that define the way in which the organization operates. Such information is usually for proprietary use by authorized personnel only. Security at this level is high. Internal Use Only: Information not approved for general circulation outside the organization, where its disclosure would inconvenience the organization or management, but is unlikely to result in financial loss or serious damage to credibility/reputation. Examples include: internal memos, internal project reports, minutes of meetings. Security at this level is controlled but normal. Public Documents: Information in the public domain: press statements, annual reports, etc. which have been approved for public use or distribution. Security at this level is minimal.
Roles and Responsibilities • Internal Roles • Executive Management; Information System Security Professionals; Owners: Data and System Owners; Custodians • Operational Staff; Users; Legal, Compliance and Privacy Officers; Internal Auditors; Physical Security Officers • External Roles • Vendors and Supplies; Contractors; Temporary Employees; Customers; Business Partners; Outsourced Relationships; Outsourced Security • Human Resources • Employee development and management; Hiring and termination; Signed employee agreements; Education
Risk Management and Analysis Risk is the likelihood that something bad will happen that causes harm to an informational asset (or the loss of the asset). A vulnerability is a weakness that could be used to endanger or cause harm to an informational asset. A threat is anything (man made or act of nature) that has the potential to cause harm. The likelihood that a threat will use a vulnerability to cause harm creates a risk. When a threat does use a vulnerability to inflict harm, it has an impact. In the context of information security, the impact is a loss of availability, integrity, and confidentiality, and possibly other losses (lost income, loss of life, loss of real property). It should be pointed out that it is not possible to identify all risks, nor is it possible to eliminate all risk. The remaining risk is called residual risk.
Risk Managementg and Analysis A risk assessment is carried out by a team of people who have knowledge of specific areas of the business. Membership of the team may vary over time as different parts of the business are assessed. The assessment may use a subjective qualitative analysis based on informed opinion (scenarios), or where reliable dollar figures and historical information is available, the analysis may use quantitative analysis For any given risk, Executive Management can choose to accept the risk based upon the relative low value of the asset, the relative low frequency of occurrence, and the relative low impact on the business. Or, leadership may choose to mitigate the risk by selecting and implementing appropriate control measures to reduce the risk. In some cases, the risk can be transferred to another business by buying insurance or out-sourcing to another business.
Risk Management and Analysis Identification of assets and estimating their value. Include: people, buildings, hardware, software, data supplies. Conduct a threat assessment. Include: Acts of nature, accidents, malicious acts originating from inside or outside the organization. Conduct a vulnerability assessment, and for each vulnerability, calculate the probability that it will be exploited. Evaluate policies, procedures, standards, training, physical security, - - - Calculate the impact that each threat would have on each asset. Use qualitative analysis or quantitative analysis. Identify, select and implement appropriate controls. Provide a proportional response. Consider productivity, cost effectiveness, and value of the asset. Evaluate the effectiveness of the control measures. Ensure the controls provide the required cost effective protection without discernible loss of productivity.
Risk Management and Analysis • Step 1: Estimate Potential Loss • SLE = AV ($) x EF (%) • SLE: Single Loss Expectancy, AV: Asset Value. EF: Exposure Factor (percentage of asset value) • Step 2: Conduct Threat Likelihood Analysis • ARO Annual Rate of Occurrence • Number of times per year that an incident is likely to occur • Step 3: Calculate ALE • ALE: Annual Loss Expectancy • ALE = SLE x ARO
Security Best Practices Job Rotation Separation of Duty Security Awareness training Ethics Education
Security Architecture and Design Computer Architecture Operating System System Architecture Security Architecture Security Models Security Models of Operation System Evaluation Methods Open Vs Closed Systems Some security threats
Computer Architecture Components Central Processing Unit (CPU) Registers Memory Units Input/output Processors Single Processor Multi-Processor Multi-Core Architecture Grids and Clouds
Operating Systems Memory Management Process management File Management Capability Domains Virtual Machines
System Architecture The software components that make up the system Middleware Database management Networks Applications
Security Architecture Security critical components of the system Trusted Computing Base Reference Monitor and Security Kernel Security Perimeter Security Policy Least Privilege
Trusted Computing Base The trusted computing base (TCB) of a computer system is the set of all hardware, firmware, and/or software components that are critical to its security, in the sense that bugs or vulnerabilities occurring inside the TCB might jeopardize the security properties of the entire system. By contrast, parts of a computer system outside the TCB must not be able to misbehave in a way that would leak any more privileges than are granted to them in accordance to the security policy. The careful design and implementation of a system's trusted computing base is paramount to its overall security. Modern operating systems strive to reduce the size of the TCB so that an exhaustive examination of its code base (by means of manual or computer-assisted software audit or program verification) becomes feasible.
Reference Monitor and Security Kernel In operating systems architecture, a reference monitor is a tamperproof, always-invoked, and small-enough-to-be-fully-tested-and-analyzed module that controls all software access to data objects or devices (verifiable). The reference monitor verifies that the request is allowed by the access control policy. For example, Windows 3.x and 9x operating systems were not built with a reference monitor, whereas the Windows NT line, which also includes Windows 2000 and Windows XP, was designed to contain a reference monitor, although it is not clear that its properties (tamperproof, etc.) have ever been independently verified, or what level of computer security it was intended to provide.
Security Models • Bell and LaPadula (BLP) Confidentiality Model • Biba Integrity Model (opposite to BLP) • Clark Wilson Integrity Model • Other Models • information Flow Model • Non Interference Model • Graham Denning Model • Harrison-Ruzzo-Ullman Model • Lattice Model
Bell and LaPadula A system state is defined to be "secure" if the only permitted access modes of subjects to objects are in accordance with a security policy. To determine whether a specific access mode is allowed, the clearance of a subject is compared to the classification of the object (more precisely, to the combination of classification and set of compartments, making up the security level) to determine if the subject is authorized for the specific access mode. The clearance/classification scheme is expressed in terms of a lattice. The model defines two mandatory access control (MAC) rules and one discretionary access control (DAC) rule with three security properties: The Simple Security Property - a subject at a given security level may not read an object at a higher security level (no read-up). The *-property (read "star"-property) - a subject at a given security level must not write to any object at a lower security level (no write-down). The *-property is also known as the Confinement property. The Discretionary Security Property - use of an access matrix to specify the discretionary access control.
Biba • In general, preservation of data integrity has three goals: • Prevent data modification by unauthorized parties • Prevent unauthorized data modification by authorized parties • Maintain internal and external consistency (i.e. data reflects the real world) • Biba security model is directed toward data integrity (rather than confidentiality) and is characterized by the phrase: "no read down, no write up". This is in contrast to the Bell-LaPadula model which is characterized by the phrase "no write down, no read up". • The Biba model defines a set of security rules similar to the Bell-LaPadula model. These rules are the reverse of the Bell-LaPadula rules: • The Simple Integrity Axiom states that a subject at a given level of integrity must not read an object at a lower integrity level (no read down). • The * (star) Integrity Axiom states that a subject at a given level of integrity must not write to any object at a higher level of integrity (no write up).
Clark Wilson Model The Clark-Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system. The model is primarily concerned with formalizing the notion of information integrity. Information integrity is maintained by preventing corruption of data items in a system due to either error or malicious intent. An integrity policy describes how the data items in the system should be kept valid from one state of the system to the next and specifies the capabilities of various principals in the system. The model defines enforcement rules and certification rules. The model’s enforcement and certification rules define data items and processes that provide the basis for an integrity policy. The core of the model is based on the notion of a transaction.
Security Modes of Operation Dedicated Systems High Compartmented Multilevel Trust and Assurance
Secure System Evaluation: TCSEC Trusted Computer System Evaluation Criteria (TCSEC) is a United States Government Department of Defense (DoD) standard that sets basic requirements for assessing the effectiveness of computer security controls built into a computer system. The TCSEC was used to evaluate, classify and select computer systems being considered for the processing, storage and retrieval of sensitive or classified information. The TCSEC, frequently referred to as the Orange Book, is the centerpiece of the DoD Rainbow Series publications. Initially issued in 1983 by the National Computer Security Center (NCSC), an arm of the National Security Agency, and then updated in 1985,. TCSEC was replaced by the Common Criteria international standard originally published in 2005.
Secure System Evaluation: TCSEC • Policy: The security policy must be explicit, well-defined and enforced by the computer system. There are two basic security policies: • Mandatory Security Policy - Enforces access control rules based directly on an individual's clearance, authorization for the information and the confidentiality level of the information being sought. Other indirect factors are physical and environmental. This policy must also accurately reflect the laws, general policies and other relevant guidance from which the rules are derived. • Marking - Systems designed to enforce a mandatory security policy must store and preserve the integrity of access control labels and retain the labels if the object is exported. • Discretionary Security Policy - Enforces a consistent set of rules for controlling and limiting access based on identified individuals who have been determined to have a need-to-know for the information.
Secure System Evaluation: TCSEC Accountability: Individual accountability regardless of policy must be enforced. A secure means must exist to ensure the access of an authorized and competent agent which can then evaluate the accountability information within a reasonable amount of time and without undue difficulty. There are three requirements under the accountability objective: Identification - The process used to recognize an individual user. Authentication - The verification of an individual user's authorization to specific categories of information. Auditing - Audit information must be selectively kept and protected so that actions affecting security can be traced to the authenticated individual. The TCSEC defines four divisions: D, C, B and A where division A has the highest security. Each division represents a significant difference in the trust an individual or organization can place on the evaluated system. Additionally divisions C, B and A are broken into a series of hierarchical subdivisions called classes: C1, C2, B1, B2, B3 and A1.
Secure System Evaluation: ITSEC The Information Technology Security Evaluation Criteria (ITSEC) is a structured set of criteria for evaluating computer security within products and systems. The ITSEC was first published in May 1990 in France, Germany, the Netherlands, and the United Kingdom based on existing work in their respective countries. Following extensive international review, Version 1.2 was subsequently published in June 1991 by the Commission of the European Communities for operational use within evaluation and certification schemes. Levels E1 – E6
Secure System Evaluation: Common Criteria The Common Criteria for Information Technology Security Evaluation (abbreviated as Common Criteria or CC) is an international standard (ISO/IEC 15408) for computer security certification. Common Criteria is a framework in which computer system users can specify their security functional and assurance requirements, vendors can then implement and/or make claims about the security attributes of their products, and testing laboratories can evaluate the products to determine if they actually meet the claims. In other words, Common Criteria provides assurance that the process of specification, implementation and evaluation of a computer security product has been conducted in a rigorous and standard manner. Levels: EAL 1 – EAL 7 (Evaluation Assurance Levels)
Certification and Accreditation Certification and Accreditation (C&A) is a process for implementing information security. It is a systematic procedure for evaluating, describing, testing and authorizing systems prior to or after a system is in operation. Certification is a comprehensive assessment of the management, operational, and technical security controls in an information system, made in support of security accreditation, to determine the extent to which the controls are implemented correctly, operating as intended, and producing the desired outcome with respect to meeting the security requirements for the system. Accreditation is the official management decision given by a senior agency official to authorize operation of an information system and to explicitly accept the risk to agency operations (including mission, functions, image, or reputation), agency assets, or individuals, based on the implementation of an agreed-upon set of security controls.
Access Control Access Control Overview Identification, Authentication, Authorization, Accountability Single Sign-on and Kerberos Access Control Models Access Control Techniques and Technologies Access Control Administration Access Control Monitoring: Intrusion Detection Threats to Access Control
Access Control Overview Access control is a system which enables an authority to control access to areas and resources in a given physical facility or computer-based information system. In computer security, access control includes authentication, authorization and audit. It also includes measures such as physical devices, including biometric scans and metal locks, hidden paths, digital signatures, encryption, social barriers, and monitoring by humans and automated systems. In any access control model, the entities that can perform actions in the system are called subjects, and the entities representing resources to which access may need to be controlled are called objects (see also Access Control Matrix). Subjects and objects should both be considered as software entities and as human users