SCSC 455 Computer Security

Chapter 1 Introduction

Dr. Frank Li

Index

Definition of Computer Security OSI Security Architecture Security Attacks Security Services Security Mechanisms Model Standards Additional Concepts: Risk, People, Security

certifications

Definition of Computer Security

Definition of Computer security page 4

There are many unauthorized computer access events and attacks on computer networks.

Do you know … Carlos Felipe Salgado used sniffing technique to

collect over 100,000 credit card numbers from online merchants.

He was arrested in June 1997 as he tried to sell them to undercover FBI agents.

On Nov. 3, 1988, system administrators all over the U.S. found that their systems were running abnormally slowly.

Overview Computer Security

Do you know … (cont’) In early 2000, a series of attacks attempt to shut

down many web sites (Yahoo, eBay, Microsoft Network, etc.) by overwhelming them with bogus requests.

Q: What are the causes of so many attacks on networks and computer systems?

Evolution of computing and security

Mainframe era The only computers were a few

mainframes, which are used for specialized tasks.

Users access the mainframes through “dumb” terminals

Little threat of security breaches or vulnerabilities being exploited at that time.

Why?

Mainframe era

Because … Only a handful of people, who knew how to operate the

computer, work in a closed environment. Although some mainframes are networked, it was done in a

crude fashion for specific tasks. Although the OS of that time had problems, software bugs,

and vulnerabilities, not many people were interested in taking advantage of them.

PC and networking era

PC and networking era (1980 -- ) Personal computers (PCs) become more efficient and

cheaper The functionality of the system grew, various applications

were developed Millions individuals have access to computers Millions of computers are networked and birth of the client

/ server computing model Many security issues emerge

Data got corrupted accidentally due to individual mistakes unexpected inputs from users malicious attempts from crackers

Pros and cons of Networking

A large number of computers are networked nowadays.

This broad access represents the power of networked computers, but also represents opportunities for malicious intent.

The more broadly a computer is networked, the more potential for access to that computer

A great deal of valuable information (personal, financial …) are stored on computers.

Two terms are commonly used to persons who break into computer systems: hacker vs. cracker.

The motivations: for fun or for profit

Other causes of computer attacks

Cyber-terrorism: the use of computing resources to intimidate or coerce others.

E.g. Hacking into a hospital computer system and changing someone's medicine prescription to a lethal dosage as an act of revenge.

Information warfare is the offensive and defensive use of information and information systems to deny, exploit, corrupt, or destroy, an adversary's information, information-based processes, information systems, and computer-based networks while protecting one's own. Such actions are designed to achieve advantages over military, political or business adversaries.

-- Dr. Ivan Goldberg Computer Crime: unauthorized access to a computer

system. Gathering accurate statistics of the damages caused

by computer crime is difficult. Why?

How are nations affected?

We are increasingly dependent on computer /networktechnology for communication, funds transfers, utilitymanagement, government services, military action, and maintainingconfidential information.

E.g. 1, A majority of the military vehicles, weapons systems, and communication systems are controlled by computer systems.

E.g. 2, Critical infrastructures and industries, such as power grid and communication channels, are controlled by computer systems. Most governments have recognized this vulnerability and have started taking steps to evade these types of attacks.

How are companies affected?

Many companies are finding out how security affects their

bottom line in ways they never expected.

If a company suffers a security breach, it will have to deal with a wide range of issues, such as sued by the customers.

Organizations have had trade secrets and intellectual property stolen by employees who left to work for a competitor.

A company can lose money and time is by its lack of readiness to react to a situation.

To get a good insurance rate, companies must prove that they have a solid security program and that they are doing all that they can to protect their own investments.

Three Key Objectives

Confidentiality Data Confidentiality Privacy

Integrity Data Integrity System Integrity

Availability

Two additional Key Objectives

Authenticity

Accountability

OSI Security Architecture

What is OSI Security Architecture Definition of threat Definition of Attack

Focus Areas Security attack

Passive attacks Active attacks

Security mechanism (Table 1.3) Security service (Table 1.2)

Five categories : authentication, Access control, Data Confidentiality, Data integrity, Nonrepudiation

Model for Network Security Two components

A security-related transformation Some secret information shared by the two principals

Four Basic Tasks in designing a security service 1 2 3 4

Other situations Unwanted access The placement that exploits vulnerabilities

Standards

NIST FIPS SP

Internet Society IETF and IAB RFC

(The next few slides are some additional concepts.)

Outsider vs. Insider

Crackers break into systems in order to: steal data e.g. credit card corrupt data

maybe unintentionally, but often for malicious reasons block access to the system

as in a Denial-of-Service (DoS) attack

Crackers are not the only threat to systems, a majority of security incidents result from the actions of users within an organization

The approaches to security

A paradox of computer security: the more secure a system is, the less usable it is.

The best approach to security is to make a system highly secure without undue annoyance to authorized users.

“Security through obscurity” assumes that if no one knows about your system, you are safe,

Is it a good approach? Why?

The approaches to security

“Security through obscurity” must be avoided.Because …The key to good security is not to hope that no one finds the security weaknesses of your system, but rather to eliminate those weaknesses.

Risk Assessment

Security should begin with a careful analysis of the assets being protected and their value

These assets can include reputation, revenue generation, secret data, or other factors

Definition of risk Risk Assessment

Computer security is really about people

Beside technology, Computer security is really about people knowing why they act as they do and knowing whom to

trust is true from the perspective of the system administrator

and the cracker

The system administrator must proceed with caution regarding where they obtain Linux and other software

A back door is a method of accessing a program that is known to its creator but not to other users

Social engineering involves a cracker manipulating a user to extract needed access information

E.g., A cracker will simply obtain a user’s name and call them in order to obtain information.

E.g. A cracker could walk past an employee’s workstation and gather information from posted data

The purpose of security certification

Two purpose of Security Certification helps companies identify individuals who have the ability,

knowledge, and experience To perform risk analysis, To identify necessary countermeasures, To implement solid security practices, To help the organization as a whole protect its facility,

network, systems, and information.

also provides security professionals with the credential that represents the skill set they want to offer to employers.

Popular IT security certifications

CompTIA Security+ and Network+ certifications (or equivalent knowledge) are helpful to prepare advanced security certifications. ( www.comptia.org )

CompTIA has more than 22,000 member companies in over 100 countries around the world;

also serves the IT industry as the world's largest developer of vendor-neutral IT certification exams.

Advanced security certifications (details next …) Certified information systems security professional (CISSP) SANS Institute offers training and information security

certifications through Global Information Assurance Certification (GIAC)

The international council of electronic commerce consultants (EC-Council) offers Certified ethical hacker (CEH)

Compare security certifications

CISSP More concerned with policies and procedures Although it is not geared toward the technical IT professional, it

has become one of the standards for many security professionals.

GIAC certifications are classified in five subject areas: Security Administration Management Operations Legal Audit

CEH certifications People with this certification will most likely be placed on a team

called a “red team” that conducts network penetration test. Probing vulnerability of the networks and computer systems.

The CISSP Requirements

CISSP exam requires one of the following professional experience requirements:

At least three years of experience in one (or more) of the ten domains and a college degree

Four years of professional experience in one (or more) of the domains within the Common Body of Knowledge (CBK)

Two years of experience plus a bachelor’s degree or a master’s degree in information security from a National Center of Excellence

Associate of CISSP For candidates who do not meet professional experience

requirements

The Common Body of Knowledge (CBK)

CISSP exam covers the ten domains that make up the CISSP CBK

Access ControlSystems andMethodology

This domain examines mechanisms and methodsused to enable administrators and managers tocontrol what subjects can access, the extent oftheir capabilities after authorization andauthentication, and the auditing and monitoring ofthese activities.

The Common Body of Knowledge (CBK)

Telecommunicationsand Network Security

This domain examines internal, external, public,and private communication systems; networkingstructures; devices; protocols; and remoteaccess and administration.

Security ManagementPractices

This domain examines the identification ofcompany assets, the proper way to determinethe necessary level of protection required, andWhat type of budget to develop for securityimplementations with the goal of reducingthreats and monetary loss.

The Common Body of Knowledge (CBK)

Applications andSystems DevelopmentSecurity

This domain examines the security componentswithin operating systems and applications andhow to best develop and measure their effectiveness. This domain looks at software lifecycles, change control, and application security.

Cryptography This domain examines methods and techniquesfor disguising data for protection purposes. This involves cryptography techniques, approaches,and technologies.

The Common Body of Knowledge (CBK)

Security Architectureand Models

This domain examines concepts, principles, and standards for designing and implementing secure applications, operating systems, and systems. This covers international security measurement standards and their meaning for different types of platforms.

Operations Security This domain examines controls over personnel, hardware, systems, and auditing and monitoring techniques. This also covers possible abusechannels and how to recognize and address them.

The Common Body of Knowledge (CBK)

Business ContinuityPlanning (BCP) andDisaster RecoveryPlanning (DRP)

This domain examines the preservation of business activities when faced with disruptions or disasters. This involves the identification ofreal risks, proper risk assessment, and countermeasure implementation.

Laws, Investigation,and Ethics

This domain examines computer crimes, laws,and regulations. This includes techniques in investigating a crime, gathering evidence, andhandling procedures. It also covers how to develop and implement an incident-handling program.

The Common Body of Knowledge (CBK)

Physical Security This domain examines threats, risks, andcountermeasures to protect facilities, hardware, data, media, and personnel. This involves Facility selection, authorized entry methods, and environmental and safety procedures.