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Secure File Transfer Protocol

(also SFTP)

Secure File Transfer Protocol definition

Secure File Transfer Protocol (SFTP) is a safe method for transferring files over a network, like the internet. It uses encryption to make sure that the data remains confidential and unchanged.

SFTP shouldn’t be confused with FTPS, another method that also secures file transfers, but uses different methods.

See also: secure connection, bulk data transfer, Secure Shell, Trivial File Transfer Protocol

History of Secure File Transfer Protocol

SFTP started as part of the Secure Shell (SSH) protocol suite, created by Tatu Ylönen in 1995. He developed it to replace the older, less safe Telnet and FTP protocols. Because of its secure nature, SFTP has become a popular choice for transferring files online.

How Secure File Transfer Protocol works

  • First, a secure SSH connection is set up between the sending device and an SFTP server. The SSH protocol provides a secure, encrypted channel over an insecure network.
  • Before the file transfer can start, the SFTP server authenticates the sender. This can involve a username and a password or a special digital key.
  • After authentication, the sender can start transferring files and doing other tasks.
  • All data sent through this SFTP link, including files, commands, and responses, is encrypted. This ensures that even if someone get their hands on the data, they can’t easily read or change it.
  • Once file transfer is done, the SFTP session ends.

Secure File Transfer Protocol uses

  • Secure file transfers. Organizations and individuals use SFTP to transfer confidential data over the internet. For example, researchers use it to share sensitive data without the risk of interception.
  • Backup. Organizations use SFTP to back up critical data to remote servers securely.
  • Web hosting. Many web hosting providers allow users to upload their website files using SFTP.
  • Remote file management. SFTP isn't limited to just uploading or downloading. It also allows remote file operations, like renaming or deleting files.
  • E-commerce and web applications. Web servers can securely receive files, such as orders or uploaded content, from users.