7 Crucial Differences Between SFTP and FTPS & Which One Should You Use

If you need to transfer files, you have many options: FTP, FTPS, HTTP, HTTPS, SFTP, SCP, WebDAV, and OFTP.

These are just a few of your choices; how do you pick the right one, particularly when security, compliance, and data governance are major concerns?

The most common way to transfer files is via File Transfer Protocol (FTP). First proposed in 1971 for use with the scientific and research network, ARPANET, FTP is easy to use and continues to be deployed by a wide range of tools for many use cases.

The problem with FTP

The major problem with FTP is its lack of data encryption and security features.

When FTP first came to the forefront, enterprises didn't face the same security challenges you have to deal with today, so its creators didn't build in data security. Commands and files are transferred in plain text, enabling users to capture sensitive information easily.

So, unless you only transfer files that contain no sensitive data, exclusively within your network firewall — you'll need an extra layer of security and a different mechanism for transmitting files.

In this article, we cover two different protocols that add security to the core of FTP:

• FTP over SSL (FTPS)
• SSH File Transfer Protocol (SFTP), also known as Secure File Transfer Protocol

As you'll see, there are several key differences between these protocols and FTP.

What is FTPS?

Dr. Taher Elgamal, Chief Scientist at Netscape from 1995 to 1998, is considered the "Father of SSL" and invented the flawless cryptographic system within SSL 3.0 to protect network communications. SSL later evolved into the modern Transport Layer Security (TLS) standard.

SSL/TLS was applied to FTP to create FTPS, producing a secure protocol for sending and receiving files across and between enterprises.

How does FTPS work?

FTPS provides two key security elements: message encryption to secure messages in transit, and client/server authentication, which validates the identities of the sender and receiver involved in a transaction.

• Secure encryption: A session key protects the data in transit; the message is encrypted with a session-specific key (TLS handshake). Once established, all messages exchanged between the client and server are encrypted.
• Authentication: The client may authenticate the sender's server identity by validating the trustworthiness of the server's certificate, and running several checks, most notably whether the certificate was issued by a trusted Certificate Authority (CA). The server authenticates the client using a username and password over a secure channel.

The sending server's certificate can be signed by a known certificate authority (CA), or your partner can self-sign it and provide you with a copy of their public certificate.

Many tools are available to send and receive files via FTPS, making it a logical choice for many file transfer situations.

Also read: Secure Alternatives to FTP

What are the disadvantages of FTPS?

One of the most common issues with FTPS is establishing connections for data transfer. In FTPS, data is transferred over a separate channel from the main channel where commands are issued. This means a new connection is made each time you list a directory or upload/download a file.

The protocol allows the data connections to be made either from the server to the client, or from the client to the server. Thus, one of the two environments must be properly prepared for this, including defining a port range to use for the data connections. The port ranges must be publicly accessible, which makes network firewall configuration more challenging.

What is SFTP?

SFTP was first designed as a proprietary protocol in 1997 and was later taken over by the Internet Engineering Task Force (IETF). SFTP is very similar in concept to FTPS. You can use it to log onto a server, upload and download files, and create and traverse directories. But the protocols themselves are quite different.

How does SFTP work?

Like FTPS, SFTP allows you to authenticate connections via a username and password. However, SFTP also lets you use public key and multi-factor authentication to enhance security further.

The encryption technology is different; unlike FTPS, which uses SSL/TLS for encryption, SFTP uses SSH.

SFTP vs. FTPS: 7 key differences

Both FTPS and SFTP provide strong protection and authentication. However, there are distinct differences between these technologies, which we will examine and explain in this section.

1. SFTP vs. FTPS security

SFTP requires that all client and server communication are secured. FTPS can switch between insecure FTP connections and FTPS secure connections. As a result, SFTP makes it easier for IT administrators to enforce security best practices within an organization by standardizing all file transfers.

Also read: How to Reduce The Most Common File Transfer Security Risks

2. SFTP vs. FTPS adoption

SFTP has wider cross-platform support than FTPS does. SSH and SFTP have a history of ubiquitous support across Unix/Linux platforms, making SFTP a better choice for most data movement projects.

3. SFTP vs. FTPS connections

FTPS uses multiple port numbers. The first port for the command channel is used for authentication and passing commands. But anytime a file transfer request or directory listing request is made, another port number must be opened for the data channel. You and your trading partners will have to open multiple ports in your firewalls for FTPS connections, which can present a security risk.

In contrast, SFTP uses only one connection. This means only one port must be open on your server, and the server only needs to be publicly accessible on the chosen port, making it easier to secure.

4. SFTP vs. FTPS authentication

SFTP and FTPS differ significantly in their authentication methods. SFTP relies on SSH (Secure Shell) for authentication, supporting various methods such as password-based, key-based, and multi-factor authentication, ensuring a secure file transfer. While FTPS uses SSL/TLS for authentication, which supports both username/password and certificate-based methods. This difference in authentication mechanisms impacts the overall security and flexibility of each file transfer protocol.

5. SFTP vs. FTPS network communication

When it comes to network communication, SFTP and FTPS have distinct characteristics. SFTP operates over a single port, typically port number 22, making it simpler to configure with firewalls. This single-port operation is a significant advantage for secure file transfer, as it reduces the complexity of firewall configurations. On the other hand, FTPS requires multiple ports; the control channel typically uses port number 21, while data channels use a range of ports. This multi-port requirement can complicate firewall settings and potentially impact the efficiency of the file transfer protocol.

6. SFTP vs. FTPS data integrity

Data integrity is another area where SFTP and FTPS differ. SFTP ensures data integrity by using SSH, which includes built-in mechanisms for verifying the integrity of the transferred data. This means that any data corruption or tampering during the transfer is detected and corrected, ensuring a secure file transfer. FTPS, on the other hand, relies on SSL/TLS to provide data integrity. While SSL/TLS also offers robust data integrity checks, the complexity of managing multiple ports and connections can sometimes lead to issues in maintaining consistent data integrity. This difference highlights the importance of choosing the right file transfer protocol based on the specific requirements for data integrity and security.

7. SFTP vs. FTPS performance

Performance is another key difference between SFTP and FTPS. SFTP’s use of a single connection and binary protocol makes it more efficient and faster for secure file transfer. The streamlined protocol and single-port operation reduce the overhead associated with managing multiple connections and SSL/TLS handshakes, resulting in better performance. On the contrary, FTPS can be slower due to the overhead of managing multiple connections and the complexity of SSL/TLS encryption. This difference in performance can be a critical factor when choosing the right file transfer protocol for high-volume or time-sensitive transfers.

SFTP vs. FTPS: Which protocol is right for you?

SFTP and FTPS are commonly used protocols for transferring files across both public and private networks. Each protocol has distinct advantages and disadvantages, and organizations should evaluate the following factors when selecting the most suitable one:

• Security: SFTP is secure by design with complete encryption, whereas FTPS boosts security by adding an extra encryption layer through SSL or TLS.
• Firewall compatibility: SFTP, using the SSH protocol, works well with firewalls, though its binary data transmissions are not ideal for logging purposes.
• Transmission speed: FTPS typically outpaces SFTP in file transmission speed, being significantly faster.
• Compatibility: While SFTP protocols might not be compatible with .NET frameworks, SFTP servers, and clients are generally more widely adopted and compatible.
• Authentication and commands: The authentication methods and FTP commands differ between SFTP and FTPS protocols.

As a result, many organizations choose to use a combination of SFTP or FTPS to take advantage of their respective strengths and offset their weaknesses. Advanced MFT solutions incorporate the capabilities of SFTP servers, FTPS, and other protocols like Secure Hypertext Transfer Protocol (HTTPS) and Secure Copy Protocol (SCP) to provide a comprehensive file transfer solution.

Also read: AS2 vs. SFTP: What Are the Main Benefits & Key Differences of Each?

CData Arc: Leverage FTPS, SFTP & other protocols with managed file transfer (MFT)

The reality is that no single FTP protocol can address every file transfer requirement for modern enterprises. Consequently, many organizations end up using a mix of different protocols and file transfer software.

Many are increasingly adopting MFT solutions to streamline their file transfers, reduce costs, and ensure security and compliance. These solutions enable them to manage, monitor, and automate file transfers using various protocols, including secure FTP (FTPS) and the SSH protocol (SFTP).

With MFT, there is no need to choose between an FTP client for FTPS or a secure shell for SFTP. Modern MFT solutions are equipped with versatile technology designed to handle all secure data transfers between computers, utilizing a variety of security protocols such as SSL and TLS. This eliminates the need to juggle multiple solutions, providing a unified and efficient approach to file management.

Also read: MFT vs. FTP: 17 Ways Managed File Transfer is Superior to File Transfer Protocol Scripting

Our flagship product, CData Arc, is a unified MFT solution that can help you manage all of your secure data transfer protocols for a variety of use cases. CData Arc can run on Windows, Apple, and Linux, right inside AWS, and even deploy in containers. It provides detailed audit logs, supports EDI protocols for partner exchanges, and can automate file encryption, workflows, and other data transfer processes. See the MFT and EDI protocols we support.

Also read: EDI Security: How to Protect Your Data Against Security & Privacy Threats in 2024

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