network security philadelphia university ahmad alghoul 2010-2011 module 1 introduction: to...

Network Security PHILADELPHIA UNIVERSITY Ahmad Alghoul 2010-2011

Module 1Module 1Introduction: To Information & Introduction: To Information & SecuritySecurity Modified by :Ahmad Al Ghoul Philadelphia University Faculty Of Administrative & Financial

Sciences Business Networking & System

Management Department Room Number 32406 Email Address: [email protected]


Objectives Information cycle, What is the role of computers in the

information cycle? What is System Security? What are we protecting? Ensure security in a network & Enhancing security by Security awareness Causes of system security lapses Security procedures & Security phases Security Goals Types of Threat, Risk, Attack Security Policy Definition and planning


Information cycle

Security is required at all phases of the information cycle – 1-gathering, 2-creating, 3-processing, 4-storing,5- transmitting and 6-deleting. Security is only as good as the weakest link in the system


UNESCO ICTLIP Module 1. Lesson 2 15

The Information Processing Cycle

ProcessDataInput

DocumentStored Data

Output

NewDocument


What is the role of computers in the information cycle?

Accept data through input devices Process data using microprocessors Store data for interactive use in the

RAM and for longer periods of storage in the hard disks

Output data through output devices.


What is System Security?

Protection of assets from unauthorized access– protection from unauthorized access both from within

and external Security is a process of reducing risk or the

likelihood of harm– Security is a weak link problem- total security is no

better than the weakest link.– It must, therefore, be evaluated across the entire

enterprise– Security is a series of trade-offs: the greater the level

of security the worse the ease of use.


What are we protecting? We are protecting system resources:

– Business information– Equipment– Systems– Data (information)

Data and Information - the most important resource:– Data is a physical phenomena that represents certain aspects of our

knowing of the world– When we process data we give it meaning and we call it information.– Data and information are:

• Stored• Moved over communication channels

We focus on security of data and information:– At source ( source: server/client)– At destination (destination: server/client)– In the communication channel

The security of computer networks means the security of information on that network.


Ensure security in a network by: Access – legal channels of getting

resources Identification – to uniquely distinguish a

user of a resource Authentication – to prove positively that

the user is what he/she claims to be. Authorization – being able to determine

and allow the user only those resources the user has ability to utilize.


Enhance security by:

Accountability – ability to associate activities with the actors.

Awareness – create a level of understanding of security issues

Administration – ability to manage the security system.


Security awareness Security is a continuous process of making

valuable resources secure. First act in securing system resources is

awareness– Process of making people understand the

implications of security in their lives – All people in the enterprise must understand the

importance of security– All people must understand the following:

• Appropriate use of resources – all people must know why security of resources matter.

• Relevancy of security• Individual’s role • Responsibility


Causes of system security weakness- Hardware – many security problems originate

from hardware failures and poor designs – Software – lots of security problems originate

from poor software designs and testing – Human/user – humans are very unpredictable

and malicious– * Resources ( data and information)– because the

resources within the computer system themselves may contain loopholes through which, if found, intruders enter the systems.


•Security procedures:

–Good and effective security is a result of a good security policy

–A policy may have one or more of the following procedures:

•For servers and Clients:

–Intrusion Detection Systems (IDS)

–Firewalls

•For the communication channel:

–Encryption

–Authentication


Security phases:– Inspection – identifying key security functions needed

and the capabilities available to achieve the desired security level

– Protection – proactive risk reduction – mechanism in place to prevent reduction in desired security level

– Detection ( in action)– to take measures to detect whether an asset has been damaged, how, and who has caused the damage.

– Response ( post-action)– to take measures that allow recovery of assets or recovery from damage, and minimize losses.

– Reflection – plans/processes that focus on security improvements.


There are 10 fundamental aspects of security ( system security): – Awareness – make every one understand the critical role security

plays in their well-being– Access – ability to connect to the system resources– Identification – to be able to know the user– Authentication – preventing unauthorized interception of

information during transmission– Authorization – allowing identifiable users access to the resources– Availability – preventing unauthorized withholding of

information and resources– Integrity – preventing unauthorized modification of information– Accuracy – an assurance of the integrity of the resources– Confidentiality – the assets of a computing system are accessible

only by authorized parties.– access to information, the source can be easily found it.


Security Goals

Confidentiality– the assets of a computing system are accessible

only by authorized parties.

Integrity– assets can be modified only by authorized

parties or only in authorized ways.

Availability– assets are accessible to authorized parties.


Fourth Objective

Securing computing resources: prevent/detect/ improper use of computing resources

• Hardware

• Software

• Data

• Network


Confidentiality

Only authorized people can see protected data.

Problems 1-who determine who is authorized? 2- what he/ she can see ?


Integrity

There are three aspects to integrity 1-Authorized action. 2-Separation and protection of resources. 3-Error detection and correction


Availability

Availability applies both to data and to service ( access to computing resources

Availability means: 1- Presence of object or service in usable

form. 2- Capacity to meet service needs. 3- Progress: bounded waiting time.


Goals of Availability

1- Timely response. 2- Fault tolerance. The ability of a computer or an

operating system to respond to a catastrophic event or fault

3-Utility or Usability ( can be used as intended)

4- Controlled concurrency: support for simultaneous access, deadlock management, and exclusive access.


Security GoalsSecurity Goals

Integrity

Confidentiality

Avalaibility


Achieving Security

Policy– What to protect?

Mechanism– How to protect?

Assurance– How good is the protection?


Threat, Risk, Attack

Threat: potential occurrence that can have an undesired effect on the system

Risk: measure of the possibility of security breaches and severity of the damage

Attack: action of malicious intruder that exploits vulnerabilities of the system to cause a threat to occur


Types of Threats Threats

– Interruption: an asset of the system becomes lost, unavailable, or unusable

– Interception: some unauthorized party has gained access to an asset

– Modification: an unauthorized party not only accesses but tampers with an asset

– Fabrication: unauthorized party fabricate counterfeit objects on a computing system


Threats to Hardware

– Interruption• denial of service

• destruction, etc.

– Interception• Theft: unauthorized product owned by other vendors


Threats to Software– Interruption

• deletion• configuration management is required

– Interception• software theft:this attack include unauthorized copying of software

– Modification• Trojan horse:a program that does one thing while covertly doing

anther• virus: a specific type of trojan horse, that can be used to spread

infection from one computer to anther.• trapdoor: a program that has a secret entry point.• information leaks: in a program, which make information accessible

to unintended people or programs• check the vendor

– use anti-virus software


Threats to Data

– Interruption(loss)• availability • include key loss(encryption)

– Interception• confidentiality

– Modification• integrity

– Fabrication• include replay attack

– internet banking


Assets vs. Threats


Security of Data


Types of Attacks (1)

Interruption – an asset is destroyed, unavailable or unusable (availability)

Interception – unauthorized party gains access to an asset (confidentiality)

Modification – unauthorized party tampers with asset (integrity)

Fabrication – unauthorized party inserts counterfeit object into the system (authenticity)


Types of Attacks (2)

Passive attacks: Eavesdropping Monitoring

Active attacks: Masquerade – one entity pretends to be a different entityReplay – passive capture of information and its retransmissionModification of messages – legitimate message is alteredDenial of service – prevents normal use of resources


Intrusion Points Intrusion points are areas that provide an access point to your

company's information. Some of these are obvious, but others are not. For instance, you might realize that you need to install a firewall to protect the internal network and computers from hackers, but if a hacker took a temporary job at your company, the firewall would be of little use. When identifying intrusion points, you must consider internal threats as well as external threats. Some internal and external access points are as follows:

Internal access points Systems that are not in a secured room Systems that do not have any local security configured External access points Network components that connect your company to the Internet Applications that are used to communicate across the Internet Communications protocols


Security Policy

Organizational Policy

Computerized Information SystemPolicy


Planning a security policy

The first, and most important, principle in security of any kind is to have a well-defined security policy. To develop a policy, you need to answer these two questions:

1. What constitutes a well-defined security policy?

2. How can I make a security policy without understanding the threats against me?


Security policy Basics

Consistent with other corporate policies Accepted by the network support staff as

well as the appropriate levels of management

Suitable for using with the existing network equipment and procedures

Compliant with local, state, and federal laws


What is a good Security policy?

A well-defined security policy outlines your requirements and limits your exposure to risk. There are three criteria for creating and evaluating a policy for information security.

1. Confidentiality: Your information must be kept private. Unauthorized access must be prevented.

2. Integrity: Your information must be protected from tampering. It cannot be modified from its original form without your authorization.

3. Availability: Your information must be available to authorized users when they need it.

network security philadelphia university ahmad alghoul 2010-2011 module 1 introduction: to...

Documents

information security

security of information

security of data

information cycle security

level of security

external security

security of computer

likelihood of harm security