When you come to the website again, the website can read Cookies and get your relevant information, so you can take corresponding actions, such as displaying a welcome slogan on the page, or allowing you to log in directly without entering an ID or password. It can be regarded as your ID card in essence. But Cookies cannot be executed as code, nor can they spread viruses, and they are exclusive to you and can only be read by the server that provides them. The saved pieces of information are stored in the form of "name-value pair", which is just a named piece of data. A website can only get the information it puts on your computer, it can't get the information from other Cookies, and it can't get anything else on your computer. Most of the contents in Cookies are encrypted, so the average user seems to be just meaningless alphanumeric combinations, and only the CGI processor of the server knows their true meaning.

Cookies are text files or data stored in the hard disk of the user's computer transmitted by the website we visit, so their storage location in the hard disk is closely related to the operating system and browser used. In Windows 9X computers, the storage location of cookies is C:/Windows/Cookies, and in Windows NT/2000/XP computers, the storage location of cookies is C:/Documents and Settings/User Name/Cookies.

IP security protocol /SSL/SSH content:

SSL(Secure Socket Layer) protocol is a secure connection technology between browser and Web server based on asymmetric key and symmetric key technology, which was introduced by Netscape Communications Company and provided at the network transport layer. It is the earliest international credit card/debit card payment agreement applied to e-commerce, which is jointly participated by consumers and businesses. SSL protocol supports the requirements of e-commerce for data security, integrity and identity authentication, but it does not guarantee non-repudiation.

Key points of SSL layer: 1. Function: Verify the final secure communication content of the application layer. (encrypted). 2. Port: A typical port running in different upper-layer applications. (Different services need to be configured with different ports+encryption methods/compression modes). Verification: Confirm the certificate and its signature. 4. Key: After authentication (double authentication if necessary), both parties obtain the key or seed through random data and key exchange protocol to complete the encryption operation.

The main purpose of SSL protocol is to provide confidentiality and reliability between two communication applications. This process is completed by three elements: (1) handshake protocol (2) recording protocol (3) warning protocol.

SSL protocol supports three kinds of authentication: mutual authentication between two parties, authentication only for the server, and no authentication for both parties.

Through the communication process of SSL protocol, SSL protocol uses asymmetric encryption algorithm to generate and exchange passwords; Check with symmetric encryption algorithm.

Data is encrypted and transmitted.

Note: 1, KI protocol is a service system for password generation and password exchange, which is mainly responsible for CA management.

2.TPS is an SSL protocol applied to HTTP service.

SSH protocol: a tool to solve the security of TELNET/FTP protocol, which supports SSH and SFTP. The encryption of Telent and FTP.

Transfer version. SSH has two versions: SSH 1 and SSH2.

2.SSH technology security verification problem: password-based and key-based verification technology.

3.SSH opportunity key verification process (server verification process) ensures that passwords will not be transmitted in the network.

SSL: Solve the security problem of the service corresponding to the HTTP protocol. Located between the transport layer and the application layer, it can provide encrypted data transmission (without signature). Principle: exchange information through SSL handshake, obtain key through verification, and encrypt data (which belongs to the data part of IP packet).

SSH: Solve the service security problem corresponding to FTP/TELNET protocol. It is located between the transport layer and the application layer, which can provide encrypted data transmission and can be signed. Related technologies: CA, PKI. Principle: Exchange information through SSH handshake (C/S access mode), obtain key through verification, and encrypt transmission (communication) data (data part of IP packet), which can also be regarded as establishing an encrypted transmission channel between systems.