HTTP and HTTPS are two important protocols for data transmission on the internet. The main difference between them is that HTTPS encrypts the transmitted data to protect it from interception and tampering, while HTTP does not. HTTP operates by default on TCP port 80 and transmits data in plaintext, while HTTPS uses SSL/TLS for data encryption and operates by default on TCP port 443. The working steps of HTTP include address parsing, DNS resolution, HTTP request packaging, establishing a TCP connection, sending a request command, server response, and closing the connection. On the other hand, the working steps of HTTPS involve an initial handshake, verifying a digital certificate, session key exchange, encrypted data transmission, and connection closure. With increasing concerns about cybersecurity, HTTPS has gradually become the preferred choice for websites requiring secure data transmission.
HTTP and HTTPS are both important protocols for data transmission on the Internet. HTTP (Hypertext Transfer Protocol) is the protocol used for transmitting hypertext on the World Wide Web, allowing efficient communication between web browsers and servers. HTTPS (Hypertext Transfer Protocol Secure) is an secure version of HTTP that encrypts the transmitted data to protect it from interception and tampering. Below is a detailed explanation of how these two protocols work:
1. Basic Concept of HTTP:
- Definition: HTTP is the protocol for transmitting hypertext on the WWW, used for communication between web browsers and servers.
- Working Port: It operates by default on TCP port 80.
- Transmission Mode: Data is transmitted in plaintext, without any form of encryption. If intercepted, the information can be easily read and altered.
2. Basic Concept of HTTPS:
- Definition: HTTPS is a secure version of HTTP that uses SSL/TLS for data encryption and integrity verification.
- Working Port: It operates by default on TCP port 443.
- Security Measures: Encrypts data to prevent interception and alteration, ensuring the security and integrity of the transmitted information.
3. Computer Communication Process:
- TCP/IP Protocol: The foundation of Internet technology, involving two key protocols: TCP (Transmission Control Protocol) and IP (Internet Protocol).
- IP’s Role: Responsible for delivering and receiving data packets across the internet, ensuring each packet reaches its destination.
- TCP's Function: Ensures data packets arrive in the correct order and attempts to confirm no content changes occurred during transmission.
4. HTTP Request and Response Model:
- Client-Server Model: The communication between the client and server follows a request/response model, with the client initiating requests and the server responding accordingly.
- Statelessness: HTTP is stateless, meaning no persistent connection needs to be established between the client and server. Each request-response exchange is independent.
5. Working Steps of HTTP:
- Address Parsing: The client's browser parses the URL to extract the protocol type, domain name, port number, and path.
- DNS Resolution: The domain name is resolved into an IP address.
- HTTP Request Packaging: The client encapsulates the request along with local information into an HTTP request data package.
- Establishing TCP Connection: Before exchanging data, a TCP connection must be established between the client and server, involving a three-way handshake process.
- Sending Request Command: Once connected, the client sends a request command to the server.
- Server Response: The server processes the request and returns an appropriate response, including status code and message.
- Closing Connection: After sending the response, the server closes the TCP connection unless specified otherwise.
6. Working Steps of HTTPS:
- Initial Handshake: Client and server establish a TCP connection, followed by an SSL/TLS handshake.
- Verifying Digital Certificate: The client verifies the server's digital certificate to ensure trustworthiness.
- Session Key Exchange: Both parties exchange session keys used for symmetric encryption of data.
- Encrypted Data Transmission: All transmitted data is encrypted to protect privacy and integrity.
- Connection Closure: The connection is closed after data exchange is complete.
In summary, while HTTP focuses on ease and speed of data transmission, HTTPS emphasizes security and data integrity. Given increasing concerns about cybersecurity, HTTPS has gradually become the preferred choice for websites requiring secure data transmission, such as online banking and shopping sites. As user awareness of security continues to rise, HTTPS is likely to replace HTTP as the standard protocol for secure communication on the internet.