Terminology » SFTP vs FTPS: Key Differences Explained

SFTP vs FTPS: Key Differences Explained

network protocol file transfer sftp ftps security

This article compares SFTP (SSH File Transfer Protocol) and FTPS (FTP over SSL/TLS), highlighting their key differences as network protocols for secure file transfer over the internet.

Specifications	SFTP (SSH File Transfer Protocol)	FTPS (FTP over SSL or FTP Secure)
Full Form	SSH File Transfer Protocol	FTP over SSL or FTP Secure
Purpose	Extends secure SSH to include easy file transfer functionality.	Extends the existing FTP protocol to include security features.
Number of Channels	1 (used for both communication and data transfer)	2 (one for communication, one for data transfer)
Message Format	Binary format (not human-readable)	Human-readable format
Popularity	Less	More
Port Number	Typically TCP port 22	Typically TCP port 21 or 990
Definition	A binary protocol where commands are packed in binary format. Messages are sent to the server, which replies in binary format.	Adds support for TLS and SSL to the existing FTP protocol. TLS stands for Transport Layer Security, and SSL stands for Secure Sockets Layer.
Framework	SSH/SFTP is not built-in to the .NET frameworks.	FTP and SSL/TLS support is available in many internet communication frameworks as built-in features.
Directory Support	Uniform and machine-readable directory listing.	Non-uniform directory listing format; requires a secondary DATA channel.
Security	Connection is always secured.	SSL/TLS has good authentication mechanisms.

Let’s delve deeper into these protocols:

SFTP (SSH File Transfer Protocol)

SFTP leverages the security of SSH (Secure Shell) to provide a safe and reliable method for transferring files. It operates over a single channel, handling both commands and data through a secure connection. Because SFTP uses binary format, the messages are not easily read by humans.

FTPS (FTP over SSL/TLS)

FTPS enhances the traditional FTP (File Transfer Protocol) with the security of SSL/TLS (Secure Sockets Layer/Transport Layer Security). This means that data is encrypted during transmission, protecting it from eavesdropping. FTPS typically uses two channels: one for commands and another for data transfer. The message format is human readable which makes debugging easier.

Key Differences Summarized

Security Foundation: SFTP is inherently secure as it is built upon SSH. FTPS adds security to FTP using SSL/TLS.
Channel Usage: SFTP uses a single channel, while FTPS uses two.
Message Format: SFTP uses a binary format; FTPS uses a human-readable format.
Framework Support: FTPS often enjoys better built-in support within various internet communication frameworks compared to SFTP.
Directory Listing: SFTP offers a standardized, machine-readable directory listing, which can simplify automation. FTPS’s directory listing is not uniform.