Overview of Network Security
The primary goal is obviously to keep unauthorized entities out and ensure the confidentiality, integrity, and availability of data. Whether a network is closed or open influences the overall security strategy employed.
- Closed Networks: Characterized by restricted access points and a limited number of entryways.
- Open Networks: More interconnected and have a higher degree of accessibility.
And understanding the basic requirements for secure data communication is essential in this context.
- Confidentiality: Ensuring that sensitive information is accessible only to authorized entities.
- Integrity: Guaranteeing the accuracy and reliability of data during transmission and storage.
- Availability: Ensuring that data and network resources are consistently accessible and operational.
- Authentication: Verifying the identity of users, devices, or systems to prevent unauthorized access.
- Access Control (Authorization): Regulating and granting permissions based on user roles and responsibilities.
Despite the presence of routers and firewalls with packet filtering capabilities, weaknesses and vulnerabilities in computer networks persist due to various factors. These vulnerabilities highlight potential weak points that could be exploited, such as:
- TCP/IP Protocol Weaknesses: Protocol vulnerabilities (HTTP, ICMP, SNMP, SMTP) can be exploited for unauthorized access or disruption.
- Operating System Weaknesses: Vulnerable operating systems (UNIX, Windows) may be exploited for unauthorized access or malicious actions.
- Network Equipment Weaknesses: Weaknesses in network equipment (lack of authentication, routing protocol vulnerabilities, misconfigurations) may lead to unauthorized access or disruption.
Types of Attacks
In general, we define a security attack to be any action that compromises the security of information owned by an organization. A general overview is provided below:
Figure 1.1 Security attacks.
A useful means of classifying security attacks, as briefly shown in the first set of notes, is in terms of passive attacks and active attacks.