In the modern Internet, HTTP and HTTPS are the two most common protocols used to transfer data between browsers and websites. Although they look similar, there are significant differences in security, data transfer, and user experience. This article will comprehensively analyze the differences between HTTP and HTTPS to help readers better understand the characteristics and application scenarios of these two protocols.

1. Basic concepts of HTTP

1. What is HTTP

HTTP, the full name of Hypertext Transfer Protocol, is an application layer protocol used to transmit hypertext data. It is the foundational protocol of the World Wide Web and defines how browsers request resources from servers and how servers respond to those requests.

2. How HTTP works

The HTTP protocol adopts a request-response model, that is, the browser sends a request to the server, and the server returns a response after processing. Both requests and responses contain two parts: header and body. The header contains information such as protocol version, status code, request method, etc., and the body contains the actual transmitted data.

3. Characteristics of HTTP

Stateless: HTTP is a stateless protocol. Each request is independent and no previous request information is recorded.

Clear text transmission: HTTP data transmission is in clear text, which means that the data can be intercepted and read during transmission.

2. Basic concepts of HTTPS

1. What is HTTPS

HTTPS, which stands for Hypertext Transfer Security Protocol, adds an SSL/TLS encryption layer to HTTP to implement encrypted transmission and authentication of data. The HTTPS protocol can effectively protect the confidentiality and integrity of data and prevent data from being stolen or tampered with during transmission.

2. How HTTPS works

When the HTTPS protocol establishes a connection, it will perform an SSL/TLS handshake process, including certificate verification, key exchange and other steps. After a successful handshake, data transmission between client and server will be encrypted. The process is roughly as follows:

The client initiates a request: The client initiates an HTTPS request to the server and sends the SSL/TLS version number and encryption algorithm list.

Server response: The server returns a response message containing the SSL/TLS certificate, which contains the server's public key.

Key exchange: The client verifies the validity of the server certificate, then generates a symmetric key, encrypts the key using the server's public key, and then sends it to the server.

Encrypted communication: The server decrypts the symmetric key, which is then used by the client and server for encrypted communication.

3. Characteristics of HTTPS

Encrypted transmission: HTTPS uses the SSL/TLS encryption protocol to ensure the confidentiality and integrity of data during transmission.

Authentication: HTTPS verifies the identity of the server through a certificate, preventing users from accessing fake websites.

Data integrity: HTTPS ensures that data will not be tampered with during transmission and ensures data integrity.

3. The main differences between HTTP and HTTPS

1. Security

HTTP: Data is transmitted in clear text, which is prone to man-in-the-middle attacks and data theft.

HTTPS: Data encrypted transmission is highly secure and can prevent data from being stolen and tampered with.

2. Performance

HTTP: Since there is no encryption overhead, HTTP transfer speeds are relatively fast.

HTTPS: Because the encryption and decryption process consumes computing resources, HTTPS has a slightly slower transmission speed. However, with the improvement and optimization of hardware performance, this difference is getting smaller and smaller in practical applications.

3. Port

HTTP: Uses port 80 by default.

HTTPS: Port 443 is used by default.

4. SEO ranking

HTTP: Search engines such as Google prefer HTTPS websites, and using HTTP may affect SEO rankings.

HTTPS: Search engines prefer HTTPS websites, which can improve the search ranking of the website.

5. Trust

HTTP: Due to the lack of encryption and authentication, HTTP websites are easily considered unsafe by users.

HTTPS: The browser will display a security lock symbol to increase user trust and improve user experience.

4. How to switch from HTTP to HTTPS

1. Obtain an SSL/TLS certificate

Obtain an SSL/TLS certificate from a trusted Certificate Authority (CA), either a free certificate (such as Let's Encrypt) or a paid certificate.

2. Configure the server

Install the SSL/TLS certificate on the server and configure the web server (such as Apache, Nginx, etc.) to support the HTTPS protocol.

3. Redirect HTTP requests

Set up the server to redirect all HTTP requests to HTTPS, ensuring that users automatically use encrypted connections when accessing the website.

4. Update website link

Update all internal links, images, scripts and other resource links in the website to HTTPS to avoid mixed content warnings.

5. SEO optimization

Submit the HTTPS version of the sitemap to search engines and update the website's robots.txt file to ensure that search engines can correctly index HTTPS pages.

in conclusion

HTTP and HTTPS are two common network protocols with significant differences in security, performance, SEO ranking, and user trust. With the increasing importance of Internet security, more and more websites are beginning to adopt the HTTPS protocol to protect users' data privacy and security. 

By fully understanding the differences between HTTP and HTTPS, enterprises and individuals can better choose the network protocol that suits them and improve website security and user experience.