Dr. Bhavani Thuraisingham

Analyzing and Securing Social Networks

Introduction to Major Modules in Cyber Security

Lecture #2

January 18, 2013

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Cyber Security

0 Security traditionally has been about CIA (Confidentiality, Integrity, Availability)

0 Security now also includes areas like Trustworthiness, Quality, Privacy

0 Dependability includes Security, Reliability and Fault Tolerance

0 Initially the term used was Computer Security (Compusec); it then evolved into Infosec – Information security – to include data and networks – now with web its called Cyber Security

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Ten Major Modules of Cyber Security0 Information Security and Risk Management

0 Security Architecture and Design

0 Access Control

0 Cryptography

0 Network Security

0 Applications Security (aka Data and Applications Security)

0 Legal Regulations, Compliance and Investigations (aka Digital Forensics)

0 Physical and Environmental Security

0 Business Continuity Planning

0 Operations Security

0 Not included: Hardware security; Performance Analysis, Ethical Hacking and Penetration Testing, - - -

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Information Security Governance and Risk Management0 Develop the information security strategy in support of business

strategy and direction.

0 Obtain senior management commitment and support

0 Ensure that definitions of roles and responsibilities throughout the enterprise include information security governance activities.

0 Establish reporting and communication channels that support information security governance activities.

0 Identify current and potential legal and regulatory issues affecting information security and assess their impact on the enterprise.

0 Establish and maintain information security policies that support business goals and objectives.

0 Ensure the development of procedures and guidelines that support information security policies.

0 Develop business case for information security program investments.

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Policies, Standards, Guidelines and Procedures

0 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.

0 Well-written policies should spell out who’s responsible for security, what needs to be protected, and what is an acceptable level of risk..

0 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.

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Policies, Standards, Guidelines and Procedures

0 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.

0 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.

0 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.

0 A security model is a scheme for specifying and enforcing security policies. Examples include: Bell and LaPadula, Biba, Access control lists

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Information Classification

0 It is essential to classify information according to its actual value and level of sensitivity in order to deploy the appropriate level of security.

0 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).

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Roles and Responsibilities

0 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

0 External Roles

- Vendors and Supplies; Contractors; Temporary Employees; Customers; Business Partners; Outsourced Relationships; Outsourced Security

0 Human Resources

- Employee development and management; Hiring and termination; Signed employee agreements; Education

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Risk Management and Analysis

0 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.

0 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.

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Risk Managementg and Analysis

0 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.

0 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

0 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.

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Risk Management and Analysis

0 Identification of assets and estimating their value. Include: people, buildings, hardware, software, data supplies.

0 Conduct a threat assessment. Include: Acts of nature, accidents, malicious acts originating from inside or outside the organization.

0 Conduct a vulnerability assessment, and for each vulnerability, calculate the probability that it will be exploited. Evaluate policies, procedures, standards, training, physical security, - - -

0 Calculate the impact that each threat would have on each asset. Use qualitative analysis or quantitative analysis.

0 Identify, select and implement appropriate controls. Provide a proportional response. Consider productivity, cost effectiveness, and value of the asset.

0 Evaluate the effectiveness of the control measures. Ensure the controls provide the required cost effective protection without discernible loss of productivity.

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Risk Management and Analysis

0 Step 1: Estimate Potential Loss

- SLE = AV ($) x EF (%)

- SLE: Single Loss Expectancy, AV: Asset Value. EF: Exposure Factor (percentage of asset value)

0 Step 2: Conduct Threat Likelihood Analysis

- ARO Annual Rate of Occurrence

- Number of times per year that an incident is likely to occur

0 Step 3: Calculate ALE

- ALE: Annual Loss Expectancy

- ALE = SLE x ARO

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Security Architecture

0 Security critical components of the system

0 Trusted Computing Base

0 Reference Monitor and Security Kernel

0 Security Perimeter

0 Security Policy

0 Least Privilege

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Trusted Computing Base

0 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.

0 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.

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Reference Monitor and Security Kernel

0 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).

0 The reference monitor verifies that the request is allowed by the access control policy.

0 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.

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Security Models

0 Bell and LaPadula (BLP) Confidentiality Model

0 Biba Integrity Model (opposite to BLP)

0 Clark Wilson Integrity Model

0 Other Models

- information Flow Model

- Non Interference Model

- Graham Denning Model

- Harrison-Ruzzo-Ullman Model

- Lattice Model

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Bell and LaPadula0 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:

0 The Simple Security Property - a subject at a given security level may not read an object at a higher security level (no read-up).

0 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.

0 The Discretionary Security Property - use of an access matrix to specify the discretionary access control.

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Secure System Evaluation: TCSEC

0 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.

0 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,.

0 TCSEC was replaced by the Common Criteria international standard originally published in 2005.

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Secure System Evaluation: ITSEC0 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.

0 Levels E1 – E6

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Secure System Evaluation: Common Criteria0 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.

0 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.

0 Levels: EAL 1 – EAL 7 (Evaluation Assurance Levels)

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Certification and Accreditation

0 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.

0 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.

0 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.

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Access Control

0 Access control models used by current systems tend to fall into one of two classes: those based on capabilities and those based on access control lists (ACLs).

0 In a capability-based model, holding an unforgeable reference or capability to an object provides access to the object

0 Access is conveyed to another party by transmitting such a capability over a secure channel.

0 In an ACL-based model, a subject's access to an object depends on whether its identity is on a list associated with the object

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Identification, Authentication, Authorization

0 Access control systems provide the essential services of identification and authentication (I&A), authorization, and accountability where:

0 identification and authentication determine who can log on to a system, and the association of users with the software subjects that they are able to control as a result of logging in;

0 authorization determines what a subject can do;

0 accountability identifies what a subject (or all subjects associated with a user) did.

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Single Sign-On

0 Single sign-on (SSO) is a property of access control of multiple, related, but independent software systems. With this property a user logs in once and gains access to all systems without being prompted to log in again at each of them. Single sign-off is the reverse property whereby a single action of signing out terminates access to multiple software systems.

0 As different applications and resources support different authentication mechanisms, single sign-on has to internally translate to and store different credentials compared to what is used for initial authentication.

0 Kerberos is an example

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Cryptography

0 Cryptography

- Mathematical manipulation of information that prevents the information being disclosed or altered

0 Cryptanalysis

- Defeating the protected mechanisms of cryptography

0 Cryptology

- Study of Cryptography and Cryptanalysis

0 ProcessI

- nput (also called Plaintext or Clear Text)

- Cryptosystem (device that performs encryption/decryption)

- Cryptographic Algorithms (Mathematical functions)

- Output (Cipher text or Cryptogram)

- Key (Crypto variable)

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Symmetric Key Cryptography

0 Symmetric-key algorithms are a class of algorithms for cryptography that use trivially related, often identical, cryptographic keys for both decryption and encryption.

0 The encryption key is trivially related to the decryption key, in that they may be identical or there is a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link.

0 The disadvantage of symmetric cryptography is that it presumes two parties have agreed on a key and been able to exchange that key in a secure manner prior to communication. This is a significant challenge. Symmetric algorithms are usually mixed with public key algorithms to obtain a blend of security and speed.

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Public Key Cryptography

0 Public-key cryptography is a cryptographic approach which involves the use of asymmetric key algorithms instead of or in addition to symmetric key algorithms.

0 Unlike symmetric key algorithms, it does not require a secure initial exchange of one or more secret keys to both sender and receiver.

0 The asymmetric key algorithms are used to create a mathematically related key pair: a secret private key and a published public key. Use of these keys allows protection of the authenticity of a message by creating a digital signature of a message using the private key, which can be verified using the public key.

0 It also allows protection of the confidentiality and integrity of a message, by public key encryption, encrypting the message using the public key, which can only be decrypted using the private key.

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Physical and Environmental Security

0 What is Physical Security

0 Planning Process

0 Protecting assets

0 Internal Support Systems

0 Perimeter Security

0 Other aspects

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Telecommunications and Network Security

0 Open Systems Interconnection Reference Model

0 TCP/IP

0 Types of Transmission

0 LAN Networking

0 Routing Protocols

0 Networking Devices

0 Networking services and protocols

0 Intranets and Extranets

0 Metropolitan Area networks

0 Remote access

0 Wireless technologies

0 Rootkits

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Legal Regulation and Compliance Investigation

0 Cyber law and Cyber crime

0 Intellectual property law

0 Privacy

0 Liability and Ramifications

0 Digital Forensics and Investigations

0 Ethics

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Applications Security

0 Database Security

0 Software and applications security issues

0 Secure systems development

0 Application development and security

0 Object-oriented systems and security

0 Distributed computing and security

0 Expert systems and security

0 Web security

0 Mobile code

0 Patch management

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Business Continuity Planning

0Project Scope Development and Planning0Business Impact Analysis (BIA) and Functional

Requirements0Business Continuity and Recovery Strategy0Plan Design and Development0 Implementation0Restoration / Disaster Recovery0Feedback and Plan Management

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Operations Security

0 Role of the Operations Department

0 Administrative Management

0 Assurance Levels

0 Configuration management

0 Media Controls

0 Data Leakage

0 Network and Resource Availability

0 Mainframes

0 Email Security

0 Vulnerability testing