In the computer security service system, security services do not include legality services of data sources. Computer security services include:

Authentication services: When an entity (such as a person or thing) claims to have a specific identity, the authentication service provides some method to verify that this claim is correct. Passwords are a common method of providing authentication services.

Access control services: Prevent unauthorized use of any resources, such as computing resources, communication resources, or information resources. For example, preventing illegal users from entering the system and legal users from illegally using system resources is the basic task of access control.

Confidentiality services: Protect information from being disclosed to entities that do not have authority to possess the information. Encryption is a common method of providing confidentiality services.

Data integrity service: Prevent data from being illegally altered or deleted during storage or transmission.

Non-repudiation service: prevents the sender or receiver from denying the sending or receiving of a message afterwards. Digital signatures are a common method of providing non-repudiation service.

Operating system hardening service: Operating systems for security hardening include Windows, Linux, AIX, HP-Unix, and Solaris. The hardening content of the operating system generally includes account management and authentication and authorization, protocol security configuration, service and exclusive configuration, etc.

Database security hardening services: Database systems for security hardening include Oracle, SQL Server, and DB2. Generally includes account management and authentication and authorization, communication protocol security management, log security configuration and auditing.