HTTP protocol is the cornerstone of the development of the Internet. However, with the rapid development of the Internet, the defects of HTTP protocol have gradually emerged. In order to make up for these defects, HTTPS protocol was born and gradually became the mainstream communication protocol. Compared with HTTP protocol, HTTPS fixes the following defects:

1. HTTPS communication encryption: HTTP protocol uses plain text when transmitting data, which means that the communication content can be easily eavesdropped and intercepted. In an unsafe network environment, hackers or malicious users can intercept HTTP communication through simple network sniffing tools and easily obtain sensitive information such as login credentials, personal identity information, etc.

To solve this security problem, HTTPS came into being. HTTPS is the full name of "Hypertext Transfer Protocol Secure", which is a combination of HTTP protocol and SSL (Secure Socket Layer) or TLS (Transport Layer Security) protocol. SSL and TLS are security protocols for encrypted communication. By establishing a secure communication line on top of HTTP, the content of HTTP communication can be encrypted and protected.

In the HTTPS communication process, the client and the server first perform the SSL/TLS handshake process, which is used to establish a secure communication line and negotiate encryption algorithms and keys. After the handshake is successful, all HTTP communication content will be transmitted through this secure line to ensure that the communication data cannot be eavesdropped or tampered with during the transmission process.

HTTPS communication encryption uses a combination of asymmetric encryption and symmetric encryption. During the SSL/TLS handshake process, an asymmetric encryption algorithm is first used to exchange keys to ensure the establishment of a secure communication line. Then, both parties use the agreed symmetric key to encrypt and decrypt subsequent communication content. Due to the high efficiency of the symmetric encryption algorithm, HTTPS communication can ensure security without significantly affecting the communication speed.

2. HTTPS content encryption: In the traditional HTTP protocol, although communication can be encrypted and protected by SSL/TLS and other methods, the content in the HTTP message is still transmitted in plain text. This means that the message body, that is, the actual data part of the HTTP request or response, is still exposed to the network and is easily eavesdropped and intercepted.

In order to further improve the security of communication, HTTPS supports encryption of the content transmitted in the HTTP message. This encryption method is called "content encryption" or "message body encryption". In this case, the client needs to encrypt the message body before sending the HTTP request to ensure that the actual data of the request is protected during transmission.

There are many ways to implement content encryption, and the commonly used methods include symmetric encryption and asymmetric encryption:

Symmetric encryption: The client and the server agree on a set of identical encryption keys, and use the keys to encrypt the main part of the HTTP message. Then, during the transmission process, only the recipient holding the corresponding key can decrypt and restore the original data. The advantage of symmetric encryption is that the encryption and decryption speed is fast, and it is suitable for the encrypted transmission of large amounts of data.

Asymmetric encryption: Also known as public key encryption, the client and the server use a pair of keys, namely a public key and a private key. The client encrypts the HTTP message body with the server's public key, and then sends the encrypted data to the server. The server uses the private key to decrypt and restore the original data. The advantage of asymmetric encryption is that it is more secure, but the encryption and decryption speed is relatively slow, and it is suitable for the encrypted transmission of small amounts of data.

Through content encryption, HTTPS ensures the complete encrypted transmission of HTTP messages, including the message header and the message body. Even if a hacker intercepts HTTPS communication, it cannot obtain the plaintext request or response data because these data have been effectively encrypted. This content encryption mechanism greatly enhances the security of communication data and protects user sensitive information and privacy.

3. Verify the identity of the communication party: The HTTP protocol cannot determine the true identity of the communication party, which may lead to threats to secure access. Through the SSL secure socket layer, the identity of the communication party can be verified using certificates. Certificates are issued by trusted third-party organizations to confirm the true existence of the server and the client. In this way, the identities of both parties in communication are verified, increasing the security of communication.

4. Ensure data integrity: HTTP cannot prove the integrity of the message, making the data likely to be tampered with. Through the security certificate authentication of the HTTPS protocol, the client and the server will negotiate a symmetric key, and the subsequent session process will use the symmetric key to encrypt the data to ensure the confidentiality of the data. After the valid data, a summary data will be added to ensure the integrity of the data. After receiving the data, the receiver will first decrypt it and then verify the summary value to determine whether the data has been tampered with.

In summary, the HTTPS protocol has successfully fixed many defects of the HTTP protocol by encrypting the communication content, verifying the identity of the communication party and ensuring data integrity, making Internet communication more secure and reliable. With the increasing importance of network security, the HTTPS protocol has become a necessity for the current Internet.