Security Attack: Expand on definition and use of “security attack”,

Security Attacks:

• any action that compromises the security of information owned by an organization
• information security is about how to prevent attacks, or failing that, to detect attacks on information-based systems
• often threat & attack used to mean same thing
• have a wide range of attacks
• can focus of generic types of attacks
• passive
• active

3 aspects of information security

consider 3 aspects of information security:

• security attack
• security mechanism
• security service

 The OSI security architecture focuses on security attacks,mechanisms,and services. These can be defined briefly as follows:

• Security attack: Any action that compromises the security of information owned by an organization.

• Security mechanism: A process (or a device incorporating such a process) that is designed to detect, prevent,or recover from a security attack.

• Security service: A processing or communication service that enhances the security of the data processing systems and the information transfers of an organization.The services are intended to counter security attacks, and they make use of one or more security mechanisms to provide the service.

OSI Security Architecture

• ITU-T X.800 “Security Architecture for OSI”
• defines a systematic way of defining and providing security requirements
• for us it provides a useful, if abstract, overview of concepts we will study

To assess effectively the security needs of an organization and to evaluate and choose various security products and policies, the manager responsible for security needs some systematic way of defining the requirements for security and characterizing the approaches to satisfying those requirements. This is difficult enough in a centralized data processing environment; with the use of local and wide area networks,the problems are compounded. ITU-T Recommendation X.800, Security Architecture for OSI, defines such a systematic approach. The OSI security architecture is useful to managers as a way of organizing the task of providing security.

Security Trends from 1990 to 2001

Discuss observed security trends (Stallings section 1.1 & Figure 1.2 above), noting growth in sophistication of attacks contrasting with decrease in skill & knowledge needed to mount an attack.

Security Trends from 1990 to 2001

Definitions Computer Security, Network Security, Internet Security

Here are some key definitions of Computer Security, Network Security, Internet Security , note boundaries between them are blurred.

• Computer Security - generic name for the collection of tools designed to protect data and to thwart hackers
• Network Security - measures to protect data during their transmission
• Internet Security - measures to protect data during their transmission over a collection of interconnected networks

our focus is on information Security which consists of measures to deter, prevent, detect, and correct security violations that involve the transmission & storage of information

Cryptography and Network Security”, 4/e, by William Stallings,

Cryptography and Network Security Background

• Information Security requirements have changed in recent times
• traditionally provided by physical and administrative mechanisms
• computer use requires automated tools to protect files and other stored information
• use of networks and communications links requires measures to protect data during transmission

The requirements of information security within an organization have undergone two major changes in the last several decades. Before the widespread use of data processing equipment,the security of information felt to be valuable to an organization was provided primarily by physical (eg. rugged filing cabinets with locks) and administrative mechanisms (eg. Personnel screening procedures during hiring process).

Growing computer use implies a need for automated tools for protecting files and other information stored on it. This is especially the case for a shared system, such as a time-sharing system, and even more so for systems that can be accessed over a public telephone network, data network, or the Internet.

The second major change that affected security is the introduction of distributed systems and the use of networks and communications facilities for carrying data between terminal user and computer and between computer and computer. Network security measures are needed to protect data during their transmission.

Operating System : Types of System Calls

Types of System Calls are:-

1. Process Control

• end, abort
• load, execute
• create process, terminate process
• allocate and free memory
• get process attributes, set process attributes

2. File management

• Create file, delete file
• Open, close
• Read, write, reposition
• Get file attributes, set file attributes

3. Device management

• Request device, release device
• Logically attach and detach devices
• Read, write, reposition
• Get device attributes, set device attributes

4. Communication

• Create, delete communication connections
• Send, receive messages
• Transfer status information
• Attach or detach remote devices