SFTP, or SSH File Transfer Protocol, is a network protocol that provides a secure method for file transfer between a client and a server. SFTP uses SSH (Secure Shell) to establish a secure connection, which ensures that the data is encrypted during transfer and thus protected from unauthorized access.
How does SFTP work?
When a user wants to transfer files using SFTP, they use an SFTP client. First the client establishes a secure SSH connection to the server, which requires user authentication through a username and password, or other authentication methods such as SSH keys. Once the connection is established, the user can perform file transfers, navigate the filesystem, create folders and change file permissions, all via an encrypted channel.
Advantages of SFTP
SFTP offers several advantages, especially when it comes to security and usability:
- Security: SFTP uses SSH to encrypt both the control and data connections, which protects against eavesdropping and man-in-the-middle attacks.
- Integrity: The data integrity is ensured, as SFTP uses checksums to verify that files have not been changed during transfer.
- Firewall-friendly: SFTP uses only a single port (usually port 22), which makes it easier to configure firewalls and NAT devices compared to traditional FTP.
Applications of SFTP
SFTP is often used in environments where data security is critical, such as:
- Businesses: For secure file transfer between offices or to customers and partners.
- Web development: For uploading and maintaining files on web servers.
- Backup and recovery: For secure transfer of backup files to external servers.