What is a Secure File Transfer Protocol?

The network protocol Secure File Transfer Protocol (SFTP) securely accesses, transfers, and manages large files and sensitive data. The Internet Engineering Task Force developed it as an extension of Secure Shell (SSH). SFTP allows for the secure transfer of files over a network, using Transport Layer Security. File transfers in virtual private network (VPN) applications commonly use it, helping enterprises meet regulatory compliance for file transfers.

How Does SFTP Work?

SFTP operates by using the same commands as the standard File Transfer Protocol (FTP), with many commands being similar or identical to Linux shell commands. It performs various tasks such as transferring sensitive files, removing files, and resuming paused transfers. To establish a connection to a server, SFTP requires a connection to the SSH port (usually port 22). Both an SFTP client and server are necessary for file transfer. The client software enables users to connect to a server and store files on it.

The network sends the data to the requesting device when a user requests a file. SFTP encrypts all files before transferring them and requires authentication to establish a secure connection. Users can choose to authenticate with a user ID and password, SSH keys, or both. The client device often stores SSH keys for automated access to servers.

Uses of SFTP

SFTP has various applications, including:

1. Complying with data standards: SFTP enables file transfer compliance with industry regulations like HIPAA and GDPR, which protect personal information and data.
2. Keeping data safe: SFTP provides security for data in transit, preventing unauthorized access by hackers or unauthorized users.
3. Complementing VPNs: SFTP users can utilize VPNs to establish a more secure and encrypted data transfer.
4. Transferring critical files and sensitive data: SFTP allows for the secure transfer of important files and sensitive data over a network.

Advantages of SFTP

SFTP offers several advantages:

1. Security: SFTP provides data security, encryption, and public key authentication, ensuring the safety of data in transit.
2. Speed: SFTP supports large file transfers and the simultaneous transfer of multiple files between servers.
3. Integration: SFTP integrates well with VPNs and firewalls, allowing for seamless file transfer within a secure network.
4. Management: The web interface or an SFTP client manages SFTP, providing flexibility and ease of use.

Disadvantages of SFTP

While SFTP has many advantages, there are some drawbacks to consider:

1. Complexity: Setting up an SFTP client can be more complicated than setting up an FTP client.
2. Private key storage: The device used for file transfer requires adequate protection to store the private keys for SFTP.
3. Compatibility issues: SFTP standards are described as optional and recommended, which may lead to compatibility issues with software developed by different vendors.

Examples of SFTP Commands

Here are some common SFTP commands:

sftp> put -- Upload a file
sftp> get -- Download a file
sftp> cd -- Change the active directory path
sftp> pwd -- Display the remote working directory
sftp> Icd -- Change the local system’s directory path
sftp> lpwd -- Display the local working directory
sftp> ls -- Display contents of the remote working directory
sftp> lls -- Display content of the local working directory
sftp> lmkdir -- Create a local directory
sftp> lumask -- Change the umask value
sftp> rename -- Rename a file on the remote host
sftp> rm -- Delete a file on the remote host

Difference between SFTP and FTP

While SFTP and FTP (File Transfer Protocol) serve similar purposes, there are some key differences:

1. Security: SFTP encrypts data before sending it to the host, while FTP does not provide encryption.
2. Architecture: FTP operates in a client-server architecture, while SFTP operates within an SSH architecture.
3. Ports used: FTP uses port 21 for inbound and outbound connections, while SFTP uses port 22 for incoming connections.
4. Method of transfer: FTP uses direct transfers, while SFTP uses tunneling, which protects transmitted data and authentication credentials.

If data security is important or regulatory compliance is required, SFTP is the recommended choice.

Conclusion

Secure File Transfer Protocol (SFTP) is a network protocol designed for secure file transfers and management. It uses encryption, authentication, and other security measures to protect data in transit. Various industries use SFTP to comply with data standards and ensure the safe transfer of critical files and sensitive data. While SFTP offers advantages such as security, speed, and integration, it also has some complexities and compatibility issues to consider. By understanding the differences between SFTP and FTP, users can make informed decisions about the best protocol for their file transfer needs.

Additional Information:

• Various SFTP clients, such as FileZilla, WinSCP, and Cyberduck, can implement SFTP.
• Many people often use SFTP in conjunction with SSH keys for secure authentication.
• Most operating systems, including Windows, macOS, and Linux, support SFTP.
• SFTP serves as a secure means of transferring files and sensitive data for both personal and business purposes.