If you use the internet, you probably encounter different protocols every day, such as HTTP, HTTPS, and FTP. But what do they mean and how do they work? In this article, you will learn about the main differences and similarities between these three common protocols, and how they affect your online communication.
Protocols are sets of rules and standards that enable computers and devices to communicate over a network, such as the internet. Protocols define how data is formatted, transmitted, and received, as well as how errors and security issues are handled. Protocols are often layered on top of each other, forming a protocol stack. For example, the TCP/IP protocol stack is the most widely used on the internet, and consists of four layers: application, transport, internet, and network access.
HTTP stands for Hypertext Transfer Protocol, and it is the protocol that governs the communication between web browsers and web servers. HTTP allows browsers to request and receive web pages, images, videos, and other resources from servers, using a standard format and method. HTTP is based on a client-server model, where the client initiates a request and the server responds with a status code and the requested data. HTTP is stateless, meaning that each request and response is independent and does not store any information about previous interactions.
HTTP's statelessness poses challenges for maintaining user interactions in web apps. For instance if you add items to a shopping cart on a website, you wouldn't want to lose them when you visit another page. State management techniques, like cookies, session storage, and local storage, overcome this. Cookies are small data pieces stored on the device (4KB). Session storage retains data for a user session (5-10MB), while local storage persists data across sessions (5-10MB). These mechanisms ensure seamless user experiences and data retention.
HTTPS stands for Hypertext Transfer Protocol Secure, and it is an extension of HTTP that adds encryption and authentication to the communication between browsers and servers. HTTPS uses a protocol called SSL (Secure Sockets Layer) or TLS (Transport Layer Security) to encrypt the data that is exchanged, preventing eavesdropping, tampering, or impersonation. HTTPS also uses certificates to verify the identity and legitimacy of the server, ensuring that the browser is connecting to the intended destination. HTTPS is indicated by a padlock icon or a green bar in the browser address bar.
TLS is the successor to SSL and is an improved and more secure version of the protocol. Some drawbacks of SSL and how TLS addressed them: - SSL had several security vulnerabilities, including the POODLE (Padding Oracle On Downgraded Legacy Encryption) attack, BEAST (Browser Exploit Against SSL/TLS), and Heartbleed vulnerability. - These vulnerabilities exposed weaknesses in SSL's cryptographic algorithms and implementation, making it susceptible to attacks that could compromise the confidentiality and integrity of data transmitted over the network. - TLS introduced stronger encryption algorithms, including AES (Advanced Encryption Standard) and SHA (Secure Hash Algorithm), to provide better security and resistance against attacks.
FTP stands for File Transfer Protocol, and it is the protocol that enables the transfer of files between computers and devices over a network. FTP allows users to upload and download files, as well as create, delete, rename, and move directories and files on a remote server. FTP is based on a client-server model, where the client establishes a connection and sends commands to the server, and the server responds with status codes and data. FTP uses two channels for communication: a control channel for commands and responses, and a data channel for file transfers.
HTTP, HTTPS, and FTP are similar in some ways, as they are all application layer protocols that use TCP (Transmission Control Protocol) as the transport layer protocol. TCP ensures that the data is reliably delivered in the correct order and without errors, by dividing it into packets, assigning sequence numbers, and using acknowledgments and retransmissions. TCP also establishes a connection between the sender and the receiver before transferring data, using a three-way handshake process. HTTP, HTTPS, and FTP also use port numbers to identify the specific service or application that is requested or offered on a server. For example, HTTP uses port 80, HTTPS uses port 443, and FTP uses port 21.
HTTP, HTTPS, and FTP are different in some ways, as they have different purposes, features, and security levels. HTTP is designed for web browsing and displaying hypertext documents that can link to other resources. HTTP is fast and simple, but not secure, as the data is transmitted in plain text and can be intercepted or modified by attackers. HTTPS is designed for secure web browsing and transactions that involve sensitive information, such as passwords, credit card numbers, or personal data. HTTPS is slower and more complex than HTTP, but more secure, as the data is encrypted and authenticated by certificates. FTP is designed for file transfer and management between computers and devices. FTP is flexible and powerful, but not secure, as the data and the credentials are transmitted in plain text and can be compromised by attackers. FTP can be secured by using SSL/TLS or other encryption methods, such as SFTP (Secure File Transfer Protocol) or FTPS (File Transfer Protocol Secure).