Secure File Transfer Protocol Secure File Transfer Protocol

What is SFTP? | Secure File Transfer Protocol

When it comes to transferring files securely over the internet, SFTP is a reliable and efficient solution. SFTP, which stands for Secure File Transfer Protocol, is a secure version of FTP that provides encryption and authentication to ensure the confidentiality and integrity of data.


What is SFTP?

SFTP is a network protocol that enables secure file transfer between a client and a server. It uses SSH (Secure Shell) as the underlying protocol to establish a secure connection. SFTP is widely used in industries that require secure file transfers, such as banking, healthcare, and e-commerce.

What is SFTP used for?

SFTP is primarily used for secure file transfers. It allows users to upload, download, and manage files securely over a network. SFTP is commonly used for:

  • Transferring sensitive data, such as financial records, personal information, and confidential documents.
  • Automating file transfers between systems or servers.
  • Backing up files to remote servers.

Features of SFTP

SFTP offers several features that make it a preferred choice for secure file transfers:

  • Encryption: SFTP encrypts data during transit, preventing unauthorized access and ensuring data confidentiality.
  • Authentication: SFTP uses SSH keys or passwords to authenticate users, ensuring that only authorized users can access the server.
  • Integrity: SFTP uses cryptographic hashes to verify the integrity of transferred files, ensuring that they have not been tampered with during transit.
  • Resume Support: SFTP allows file transfers to be resumed from where they left off, even if the connection is interrupted.

How does SFTP work?

SFTP works by establishing a secure connection between a client and a server. Secure File Transfer Protocol works by providing a secure and encrypted method for transferring files between computers over potentially unsecured networks. Here’s how it works:

  1. Authentication: The process begins with authentication. When a user wants to transfer files using SFTP, they must authenticate themselves to the server. This authentication can be done in a few different ways, including using a username and password or SSH (Secure Shell) keys. SSH keys are highly secure and often preferred for their robust protection.
  2. Secure Connection: Once authenticated, SFTP establishes a secure connection between the client (the user’s device) and the server (the remote computer or system). This connection is encrypted, which means that any data transferred between the client and server is scrambled and can only be unscrambled by the recipient. This encryption prevents unauthorized access or data interception during transmission.
  3. Data Transfer: With the secure connection in place, data transfer can begin. The user can upload, download, or manipulate files and directories on the server, depending on their permissions and access rights. All data exchanged between the client and the server is protected by encryption, ensuring data privacy and integrity.
  4. Data Integrity: SFTP also includes mechanisms to ensure data integrity. This means that the data remains unchanged during transmission. If any unauthorized alterations occur during the transfer, SFTP can detect this and notify the user.
  5. Platform Independence: SFTP is platform-independent, meaning it can be used on various operating systems, including Windows, Linux, macOS, and more. This versatility makes it a convenient choice for users regardless of their preferred system.

SFTP works by creating a secure and encrypted connection between a user’s device (the client) and a remote server. This connection safeguards the data during transfer, ensuring that it remains confidential and intact. The authentication methods, encryption, and data integrity features make SFTP a reliable choice for secure file transfers.


SFTP Port Number

The default port number for SFTP is 22, which is the same as SSH. However, the port number can be configured on both the client and server sides if needed.


SFTP is known for its high level of security, encryption, and versatile authentication methods, making it a top choice for protecting data during transfer. FTPS adds security to standard FTP using encryption but can be more complex to set up. FTP, while user-friendly, lacks the encryption and security features of SFTP and FTPS, making it less suitable for transferring sensitive data. The choice between these protocols should depend on the specific security and ease-of-use requirements of your file transfer needs.

  • SFTP: Provides secure file transfer over SSH. It encrypts both the data and the commands, ensuring confidentiality and integrity.
  • FTP: Stands for File Transfer Protocol. It is an older protocol that transfers files in plaintext, making it less secure.
  • FTPS: Stands for FTP over SSL/TLS. It adds SSL/TLS encryption to FTP, providing a secure connection. However, it requires a separate SSL/TLS certificate.

Certainly, here’s a comparison of SFTP, FTP, and FTPS in a table format:

FeatureSFTP (Secure File Transfer Protocol)FTP (File Transfer Protocol)FTPS (FTP Secure)
SecurityHighly secure with encryption and authentication. Data is encrypted during transmission.Less secure as data is transferred in plaintext. Security relies on additional layers.Secure with data encryption, but setting up certificates can be complex.
AuthenticationSupports various authentication methods, including password-based and key-based authentication.Typically relies on usernames and passwords, which are less secure.Offers various authentication methods, including certificates and passwords.
PortUses a dedicated port, typically port 22, for secure data transfer.Uses two ports, 20 for data and 21 for control, which can be restrictive in some network environments.Uses the same ports as FTP, which can be less secure.
Ease of SetupGenerally straightforward to set up, especially with key-based authentication.Simpler to set up but less secure by default.Can be more complex due to certificate management, but provides strong security.
Platform SupportCompatible with various operating systems, including Windows, Linux, and macOS.Widely supported across different platforms.Supported on multiple operating systems.
Resource UsageEncrypting and decrypting data may consume more system resources, potentially affecting transfer speeds.Light on system resources, making it faster for data transfer.Resource-intensive due to encryption, possibly impacting performance.
Data IntegrityEnsures that data remains intact and unaltered during transmission.Offers no built-in data integrity checks. Data integrity must be ensured separately.Includes data integrity checks, which can add complexity.

SFTP stands out for its security, encryption, and authentication options. FTP is less secure due to its reliance on plaintext transfer, while FTPS offers security through encryption but can be more complex to set up. The choice between these protocols depends on your specific needs and the level of security required for your file transfers.


SFTP Clients

There are several SFTP clients available that allow users to connect to SFTP servers and transfer files securely. Some popular SFTP clients include:

  • FileZilla
  • WinSCP
  • Cyberduck
  • SSH File Transfer

Advantages and Disadvantages of SFTP


Advantages of using SFTP

  • Security: SFTP provides encryption and authentication, ensuring the confidentiality and integrity of data.
  • Platform Independence: SFTP is supported on various operating systems, including Windows, Linux, and macOS.
  • Resume Support: SFTP allows file transfers to be resumed from where they left off, minimizing the impact of connection interruptions.

Disadvantages of using SFTP

  • Complex Setup: Setting up an SFTP server can be more complex compared to FTP.
  • Performance: SFTP may have slower transfer speeds compared to FTP.
  • Port Number Limitation: SFTP uses port 22 by default, which may be blocked by firewalls or restricted in certain environments.

SFTP is a secure and reliable solution for file transfer. It provides encryption, authentication, and integrity checks to ensure the confidentiality and integrity of data. With its features and advantages, SFTP is widely used in industries that require secure file transfers. However, it’s important to consider the specific requirements and limitations of SFTP before implementing it in your organization.

Leave a Reply

Your email address will not be published. Required fields are marked *