Reading notes for the first chapter of "Cryptography and Network Security"

• Classification of cryptographic algorithms and protocols: symmetric encryption, asymmetric encryption, data integrity algorithms, authentication protocols

1.1 Computer security concepts

• Definition (from NIST): For an automated information system, protective measures are taken to ensure the integrity, availability, and confidentiality of information system resources (including hardware, software, firmware, information/data, and communications) [CIA Triplet].
  ① Lack of confidentiality is defined as the unauthorized disclosure of information
  ② Lack of integrity is defined as unauthorized modification and destruction of information
  ③ Lack of availability is the interruption of access to and use of information and information systems
  In addition: authenticity and traceability

1.2 OSI Security Framework

To effectively evaluate an organization's security needs, and to evaluate and select various security products and policies

1.3 Security attacks

Category: passive attack and active attack

• Passive attack: Eavesdropping and monitoring of transmissions. Including information security leakage and traffic analysis.
• Active attack: modify or forge data flow
• Classification of active attacks: masquerading, replay, message modification, denial of service

1.4 Security services

Definition: [X.800] - A service provided by the protocol layer of a communication open system to ensure sufficient security of the system or data transmission [
RFC 4949] - It is a process or process provided by the system for special protection of system resources. Communication services and security services implement security policies through security mechanisms.

1. Authentication: Ensure communication authenticity
2. Access control
3. Data confidentiality
4. data integrity
5. non-repudiation
6. Availability service