SFTP protocol

FTP (File Transfer Protocol) is a protocol for transferring data over a network. It was invented more than 30 years ago and has a significant disadvantage - the lack of reliable security mechanisms. All data transmitted via FTP is sent in an open form, which makes it easily accessible to intruders.
Fortunately, there are more secure alternatives to FTP in modern networking technologies. For example, the SFTP (SSH File Transfer Protocol) provides data encryption and secure file transfer.
SFTP prevents intruders from intercepting data packets and reading information. By using encryption, all files and data remain confidential and inaccessible to third parties.
 

How the SFTP protocol came to be

The solution to the security problem was to combine two protocols - FTP and SSL. Later, with the emergence of the more secure TLS protocol, FTP was merged with it as well. This is how FTPS came into being - an extended version of the usual FTP with the addition of encrypted sessions from SSL/TLS.
 

SFTP - what it is in simple words

Later, in collaboration with SSH, the SFTP protocol - Secure File Transfer Protocol or SSH File Transfer Protocol - appeared. It provides secure file transfer via SSH and provides access to all accounts on the remote SFTP server.
 

SFTP and FTP - what is the difference?

SFTP is an improved version of file transfer protocol that addresses the security issues that FTP has. It has tools for password encryption and authentication. For example, one way to authenticate in SFTP is to use encryption keys. When a user connects to an SFTP server, they provide their public key, which is checked at the server to confirm identity.
In addition, the SFTP password is encrypted and transmitted over an encrypted network channel, which prevents malicious users from intercepting it.
SFTP authenticates the source through certificates - this ensures that only authorized users access the server.
SFTP thus provides a more secure environment for connection, protecting passwords, authentication and data transfer. It is an improved version of FTP that puts security first.
 

How SFTP works

• When the client wants to send data to the server, it sends a request through port 22, which is used for secure SSH connection.
• The server accepts it and proceeds to encrypt the data using a special SSH algorithm.
• The server then sends the encrypted data back to the client over a secure channel, which ensures that the transmission is secure.
• Then the client, using SSH authentication, decrypts the received data for further use.

While it cannot be said with certainty that data transmitted via SFTP is 100% impossible to steal, its protection provides a high level of difficulty for unauthorized access.
 

Which is better FTP or SFTP?

The updated SFTP has many pluses that tilt the user's scales in its favor.

• Increased security and data privacy is the most obvious advantage of SFTP over its predecessors. SFTP uses a more secure method of authentication and encryption of the session on the Internet using keys, which prevents the possibility of unauthorized access and information leakage in case of wrong passwords or unauthorized access attempts.
• You can transfer files of any size, unlike FTP, which has a restriction of 2 GB.
• SFTP uses an advanced data transfer protocol that significantly reduces process time. In particular, the compression method is used to reduce the amount of information transferred.
• Convenient ability to pause and resume data transfer. This is especially useful when transferring large files, as it allows you to regulate the process and avoid resending if there are network problems.
• SFTP allows you to stop data transfer completely if necessary, for example in case of connectivity problems or changes in requirements.
• SFTP provides the user with the ability to execute various commands to control data transfers, which provides flexibility when working with files and folders.
• Additional information about files (creator, creation date and access permissions) is also transferred with the files.

In addition, SFTP can be integrated into your existing production environment, making it easier to automate data transfer and improve the efficiency of information sharing within your company.
SFTP also has the disadvantage of not being as widespread and popular as its big brother FTP. This has led to limited support for SFTP among websites, servers, routers, switches, firewalls, and other devices. To use SFTP, you need to install a program - an FTP client - on your computer. Not all FTP clients support SFTP connections (as opposed to FTP support), so you must first make sure that the devices and programs involved in the exchange process support the secure protocol. You can perform SFTP operations via the command line. For example, the "sftp" command allows you to establish a connection to a remote server and transfer files in secure mode
 

Clients using the SFTP protocol

There are several variants of FTP clients that you will find on the Internet. Some of them work in a graphical user interface (GUI), which makes using the program more convenient and intuitive.
The most common FTP/SFTP clients with GUI are FileZilla, WinSCP and Cyberduck, which allow you to easily send and open files from your computer to a remote server, and vice versa. They also provide additional features: support for multiple connections and customization of configuration settings. Lesser known but no less convenient SFTP clients: Free FTP, sFTP, Bitvise, FTPManager, Transmit 5, WS_FTP.
 

Summary

The secure version of FTP solves the problem of privacy of data transmitted over a network. SFTP is less common than the older version - FTP - but is more secure and functional.