The Difference Between FTP vs SFTP

TLDR: Understanding the difference between FTP and SFTP is critical for organizations handling sensitive information. While the FTP protocol operates unencrypted, transmitting data over ports 20 and 21 without security, SFTP (SSH File Transfer Protocol) provides secure FTP capabilities by operating over port 22 with built-in encryption and authentication. The SFTP protocol uses SSH to encrypt all data in transit, protecting credentials and files from interception. However, both FTP over SSH and standard SFTP face performance limitations on high-latency networks. For organizations requiring both security and speed, modern alternatives like IBM Aspera FASP eliminate these constraints while providing enterprise-grade encryption, making them superior to FTPS or SCP for large-scale secure file transfers.

FTP refers to an application layer protocol that’s used for transferring files between a client and a server, one of the simplest and earliest mechanisms created to move files. SFTP builds on the concepts of FTP software, leveraging the secure shell (SSH) protocol for additional security.

Moving data, information, and content is paramount in most industries. Transferring this information securely is essential in today’s world. Many companies cannot afford for any of their files or data to fall into the wrong hands, a mistake that could mean a devastating security breach and lead to many different consequences for a company. There are many different file transfer solutions in the virtual space, two of which are FTP vs SFTP.

FTP vs SFTP: Complete Protocol Comparison

Feature	FTP (File Transfer Protocol)	SFTP (SSH File Transfer Protocol)	FTPS (FTP Secure)	IBM Aspera FASP
Full Name	File Transfer Protocol	SSH File Transfer Protocol	FTP over SSL/TLS	Fast, Adaptive, and Secure Protocol
Security Level	Unencrypted – No security	Encrypted via SSH	Encrypted via SSL/TLS	Military-grade AES encryption
Port Numbers	Ports 20 (data) and 21 (command)	Port 22 (single SSH connection)	Port 21 + dynamic ports	Configurable UDP ports
Authentication	Plain text credentials	Secure SSH authentication (keys or passwords)	SSL certificate authentication	Token-based secure authentication
Data Encryption	None – sensitive information exposed	Full encryption via SSH tunnel	Full SSL/TLS encryption	End-to-end AES encryption
How It Works	Separate command and data channels	Single encrypted SSH channel	FTP with SSL/TLS wrapper	UDP-based with reliability layer
Protocol Type	FTP Protocol (TCP-based)	SFTP Protocol (SSH-based)	FTP over SSH alternative (TCP)	Proprietary UDP-based protocol
Use SFTP When	Never for sensitive data	Basic secure transfers needed	Legacy SSL/TLS systems	Not applicable – use Aspera
Firewall Configuration	Complex – multiple ports	Simple – port 22 only	Very complex – dynamic ports	Simplified – configurable
Transfer Speed	Limited by TCP	Limited by TCP and SSH overhead	Limited by TCP and SSL overhead	Maximum – up to 1000x faster
Latency Impact	Severely degraded	Severely degraded	Severely degraded	Minimal – consistent performance
SFTP Uses Cases	Public file sharing only	Secure file transfers, remote access	Organizations requiring SSL compliance	Not applicable
Key Management	None required	SSH keys required	SSL certificates required	Simplified token management
Compliance	Non-compliant for regulated data	Meets basic security standards	Meets SSL/TLS requirements	Exceeds enterprise standards
Best For	Obsolete – no longer recommended	Small secure transfers	Legacy systems needing encryption	Enterprise-scale secure transfers

Understanding the Difference: The difference between SFTP and FTP fundamentally comes down to security. While FTP transmits everything unencrypted, SFTP uses the SSH File Transfer Protocol to encrypt data, commands, and authentication. However, neither protocol addresses the performance limitations inherent in TCP-based transfers, which is why organizations increasingly turn to purpose-built solutions like IBM Aspera for combining security with breakthrough transfer speeds.

What is FTP?

File Transfer Protocol (FTP) refers to an application layer protocol that’s used for transferring files between a client and a server. It is one of the oldest protocols, allowing users to sign in and access files like data, videos, pictures, and other types of content. Users connect to an FTP server with an FTP client, which gives you access to download and upload files from the server.

FTP uses two basic channels to operate: the command channel and data channel. The command channel carries information about the task itself, while the data channel transfers the actual file between devices. It is one of the simplest and earliest mechanisms created to move files from one place to another.

What is SFTP?

While FTP is the standard method of transferring files or data between computers, but it is outdated technology in today’s security-conscious environment. Secure File Transfer Protocol (SFTP) is a network protocol for transferring, accessing, and managing files between two machines. It is built on the concepts of FTP software, leveraging the secure shell (SSH) protocol for additional security. This requires the client to be authenticated by the server.

This requires an SFTP client and server. The client is the software that provides the access to upload and download files to and from the remote server. The SFTP server is where the files are stored and retrieved from.

Choosing FTP vs SFTP

If you are looking for a simple, basic system to transfer files, you may consider FTP. If you are looking for a more secure option that requires an added layer of protection for your transfer than FTP, SFTP might be the better alternative. Unfortunately, SSH has many protection features that systems using secure keys like SFTP require, making it hard to maintain and manage. Without support from a software vendor, it can also be difficult to configure properly. Another problem that can arise is the susceptibility to network congestion and packet loss resulting in slow transfer speeds.

Understanding the Difference Between FTP and SFTP

• The FTP protocol transmits all data unencrypted, exposing sensitive information including login credentials and file contents to potential interception
• SFTP (SSH File Transfer Protocol) operates over port 22 and uses SSH encryption to secure all data transfers and authentication
• The difference between SFTP and standard FTP is fundamental: SFTP provides complete encryption while FTP offers no protection
• SFTP uses a single encrypted channel rather than FTP’s separate command and data connections, simplifying firewall configuration

Security Considerations

• Organizations should never use standard FTP for transferring sensitive information or confidential business data
• SFTP protocol implementation requires proper SSH key management and authentication controls to maintain security
• FTPS (FTP Secure) provides an alternative to SFTP by adding SSL/TLS encryption to traditional FTP connections
• SCP (Secure Copy Protocol) offers another SSH-based option but lacks SFTP’s advanced file management capabilities
• FTP over SSH implementations, whether SFTP or FTPS, encrypt data in transit but still inherit TCP’s performance limitations

When to Use SFTP

• Use SFTP when replacing unencrypted FTP systems that currently handle sensitive business files
• SFTP protocol is suitable for organizations requiring basic secure file transfers without complex infrastructure changes
• The SFTP uses SSH framework makes it compatible with existing security policies and key management systems
• Consider SFTP for remote server administration and automated secure file synchronization tasks

Technical Implementation

• SFTP operates exclusively through port 22, eliminating the firewall complexity associated with FTP’s multiple ports
• The SSH File Transfer Protocol provides strong authentication through public key cryptography or password-based methods
• FTPS requires managing SSL certificates in addition to FTP credentials, adding administrative complexity
• Both SFTP and FTPS encrypt connections but cannot overcome TCP’s fundamental speed limitations on long-distance transfers

Performance and Scalability Limitations

• Both FTP and SFTP suffer from TCP-based performance degradation across high-latency, long-distance network connections
• SSH encryption overhead in SFTP reduces throughput compared to unencrypted FTP, though security benefits justify this trade-off
• Organizations transferring large datasets globally find that neither FTP protocol nor SFTP can utilize available bandwidth effectively
• Network congestion and packet loss disproportionately impact FTP and SFTP performance compared to UDP-based alternatives

Modern Secure Transfer Solutions

• IBM Aspera’s FASP protocol combines military-grade encryption with speeds up to 1000x faster than SFTP
• Unlike FTP over SSH solutions, Aspera maintains consistent throughput regardless of distance, latency, or packet loss
• Aspera eliminates the choice between security and performance, delivering both simultaneously through patented technology
• Organizations requiring secure FTP alternatives should evaluate Aspera for enterprise-scale file transfer requirements

Decision Framework

• Replace all unencrypted FTP systems immediately to protect sensitive information from interception
• Use SFTP for basic secure transfers when transfer speed and volume are not primary concerns
• Consider FTPS only when SSL/TLS compliance specifically requires it over SSH-based protocols
• Choose IBM Aspera when your organization needs to encrypt large file transfers while maintaining maximum throughput
• Contact PacGenesis to assess which secure file transfer protocol best addresses your specific security, performance, and compliance requirements

Understanding the difference between these protocols empowers informed decisions about protecting your organization’s data. While SFTP provides essential security improvements over unencrypted FTP, modern enterprise demands often require the advanced capabilities that only purpose-built solutions like IBM Aspera can deliver.

IBM Aspera: A Secure Alternative to FTP and SFTP

An alternative to both FTP and SFTP, Aspera uses a proprietary FASP technology to deliver data. It eliminates bottlenecks associated with outdated technology and moves files at maximum speeds, fully utilizing the available bandwidth. Aspera is run on a cloud-based infrastructure, meaning there is no need to provision the underlying infrastructure.

There are many benefits that Aspera can offer:

• Deliver videos and grow files, as well as exchange files and data sets of any size quickly and reliably around the world
• Patented adaptive rate control to quickly ramp up and fully utilize a shared network’s bandwidth, still allowing other TCP-based applications to function properly
• FASP protocol offers built-in security for data transfers using AES encryption standard through the open-source OpenSSL toolkit

Learn More About Aspera with PacGenesis

At PacGenesis, we have earned IBM’s trust to implement their Aspera solution as an IBM Gold Business Partner. We’ve also spent the last 10 years helping businesses focus on scalable, secure data transfer and workflow solutions to fit their needs. To learn more about Aspera, contact us for a consultation.
To learn more about PacGenesis, follow @PacGenesis on Facebook, Twitter, and LinkedIn or visit pacgenesis.com.

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