In the Internet world, HTTP and HTTPS are the two protocols we come into contact with most every day. They have important differences in data transmission and security.

Without spending too much time, let us understand the key differences between HTTP and HTTPS concisely and clearly, and reveal the mysteries of network communication for you.

1. What is HTTP protocol?

HTTP (Hypertext Transfer Protocol) protocol is a protocol used to transfer hypertext between computers.

It is one of the most widely used protocols on the Internet and is used to transfer data between web browsers and web servers.

HTTP is a stateless, connectionless protocol, each request-response interaction is independent, and the server does not retain any information between requests.

HTTP is based on the client-server model, where the client is the party that initiates the request and the server is the party that provides the service.

Typically, the client is the web browser used by the user, while the server is the computer that stores and serves web pages.

The basic workflow of HTTP includes:

• Establish a link: The client establishes a connection with the server through the TCP/IP protocol. The default port is 80.
• Send a request: The client sends an HTTP request to the server. The request contains the request method (GET, POST, etc.), the path to the target resource, the protocol version and other information.
• Processing the request: After the server receives the request, it processes it according to the content of the request and the resources on the server.
• Send response: The server sends an HTTP response to the client. The response contains information such as status code, response header, and response body.
• Closing the connection: Once a request-response is complete, the connection can be closed, or kept open for subsequent requests.

HTTP defines a variety of request methods, including:

• GET: Get resources from the server.
• POST: Submit data to the server for updating resources.
• PUT: Create or update resources on the server.
• DELETE: Delete resources from the server.

The HTTP protocol is the basis for building many applications on the Internet. It allows hypertext content such as text, images, audio, and video to be easily transferred between computers around the world.

2. What is HTTPs protocol?

The HTTPS (Hypertext Transfer Protocol Secure) protocol is a secure version of the HTTP protocol. It ensures the security and privacy of data transmission by adding an encryption layer between HTTP and Transport Layer Security (TLS).

The predecessor of TLS was SSL (Secure Sockets Layer), but it had some security problems, so it was replaced by TLS.

The main goal of HTTPS is to prevent data from being eavesdropped, tampered with, or forged by encrypting communication content.

It adds a secure TLS/SSL layer to the communication layer between HTTP and TCP, which uses public key cryptography to ensure the confidentiality and integrity of communications.

Here’s how HTTPS works:

• Handshake process: The client initiates a connection request with the server, and the server returns a digital certificate (including the public key) and the encryption algorithm supported by the server.
• Key exchange: The client encrypts a randomly generated symmetric key using the server's public key and sends it back to the server.
• Establishing a secure connection: The server uses the private key to decrypt the random key sent by the client, and both use this random key to encrypt and decrypt the communication.
• Secure transmission: The client and server use negotiated symmetric keys for encryption and decryption to ensure the confidentiality of communication content.

The advantages of HTTPS include:

• Data encryption: Prevent third parties from eavesdropping by encrypting communication content.
• Authentication: Verify the identity of the server through digital certificates to prevent man-in-the-middle attacks.
• Data integrity: Encryption and digital signatures ensure data is not tampered with during transmission.

HTTPS is often used to protect the transmission of sensitive information, such as login information, payment information, etc., making the communication between users and websites more secure and trustworthy.

Most websites use HTTPS to provide a higher level of security when handling user data.

3. What is the difference between HTTP protocol and HTTPS protocol?

HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) are two different protocols. They have some key differences in data transmission and security:

1) Security:

• HTTP: It is a clear text transmission protocol. Data is not encrypted during transmission and is easily eavesdropped and tampered by third parties.
• HTTPS: Encrypted using the TLS/SSL protocol, ensuring the security and privacy of data transmission by adding an encryption layer between HTTP and the transport layer.

2)Default port:

• HTTP: Uses port 80 by default.
• HTTPS: Port 443 is used by default.

3) Protocol identification:

• HTTP: URL starts with "http://".
• HTTPS: URL starts with "https://".

4) Data transmission method:

• HTTP: Clear text transmission, data is not encrypted.
• HTTPS: Use TLS/SSL encryption to protect the security of data during transmission.

5) Certificate:

• HTTP: No need to use digital certificates.
• HTTPS: Requires a digital certificate to authenticate to the server.

6) Connection method:

• HTTP: stateless, each request and response are independent.
• HTTPS: stateless, each request and response are independent, but the security of communication is ensured through encryption.

7) Usage scenarios:

• HTTP: Suitable for scenarios that do not involve the transmission of sensitive information, such as general web browsing.
• HTTPS: Suitable for scenarios where user privacy and sensitive information transmission need to be protected, such as login, payment, etc.

In general, HTTPS adds a security layer to HTTP to protect the security of data transmission through encryption and authentication.

In scenarios involving user privacy and sensitive information, the use of HTTPS is highly recommended to provide a higher level of security and trust.