TLDR: SFTP (Secure File Transfer Protocol) is a network protocol that enables organizations to transfer files securely through SSH encryption. SFTP uses SSH protocol connections on the SFTP port (port 22) to establish secure connections between an FTP client and SSH server, protecting data security through end-to-end encryption. The SFTP protocol provides robust file management capabilities, allowing users to manage files, implement access controls, and transfer both large file datasets and remote file collections while maintaining file attributes like timestamps. Organizations use SFTP for managed file transfer operations because it leverages SSH key authentication and the secure SSH connection to ensure encryption of all data in transit. SFTP work involves establishing an SSH connection, authenticating via SSH keys or passwords, then executing SFTP file transfer commands for secure file access. Understanding the difference between SFTP and standard FTP is critical—while both enable file management operations, only SFTP uses SSH to encrypt credentials and content, making it essential for data security compliance and protecting sensitive information during transfer.
When it comes to secure file transfer, SFTP (Secure File Transfer Protocol) offers a significant improvement over traditional FTP by providing encrypted file transfers through a secure channel established via SSH (Secure Shell). SFTP transfers data over Port 22 and supports robust authentication methods, including public/private key pairs. For businesses handling sensitive data, SFTP ensures secure file delivery between an SFTP client and an SFTP server. However, even SFTP has its limitations—particularly in speed and scalability.
To address these gaps, solutions like IBM Aspera, built on the FASP protocol, offer dramatically faster and more resilient file transfer capabilities. FASP can outperform SFTP by 100x or more, making it a powerful tool for organizations needing high-speed data transfer and collaboration.
The fundamental concepts of FTP and SFTP are close in design. Both FTP and SFTP use clients and servers to communicate over the internet; however, when it comes to security and data transfer they are much different. SFTP in comparison to FTP has extra built-in security measures that FTP simply does not. SFTP stands for SSH File Transfer Protocol. This protocol has improvements over FTP, and is designed to include an SSH level data transfer strategy in transit. Furthermore, SFTP can preserve file attributes such as timestamps, which FTP cannot.
Another important consideration around both SFTP and FTP is in the manner in which data is sent. These protocols are built on a sluggish transmission framework known as TCP. TCP sends data in an in-order manner that is dependent on a few initiating acknowledgments between the client and host. Once established, the data is transmitted one packet at a time, always checking for no packet data loss.
An SFTP server is a system configured to support secure file transfer over the Secure File Transfer Protocol (SFTP). Unlike traditional FTP servers, an SFTP server operates over Port 22 using SSH (Secure Shell) to establish a secure, encrypted channel for data transmission. This ensures that any file transfer between an SFTP client and the server remains protected from interception or tampering.
SFTP servers support multiple methods of authentication, such as usernames and passwords, or more securely, public key and private key pair-based authentication. These features make SFTP a reliable solution for enterprises looking to implement compliant, encrypted data transfer processes.
| Feature | Standard FTP | SFTP (SSH File Transfer Protocol) | IBM Aspera FASP |
|---|---|---|---|
| Encryption | None – unencrypted | Full SSH protocol encryption | Military-grade AES-256 encryption |
| SFTP Port | Ports 20 & 21 | Port 22 (SSH connection) | Configurable UDP ports |
| Authentication | Plain text passwords | SSH key or password via SSH protocol | Token-based secure authentication |
| Data Security | No protection | Complete encryption via SSH | End-to-end encryption with integrity checks |
| Secure Connection | Not available | SSH connection required | Optimized secure channel |
| File Management | Basic file access | Full file management with permissions | Advanced file management + metadata |
| Manage Files Capability | Upload/download only | Manage files, directories, access controls | Complete workflow management |
| SSH Server Required | No | Yes – SFTP uses SSH | No – proprietary protocol |
| FTP Client Compatibility | Standard FTP clients | Requires SFTP-capable FTP client | Aspera client software |
| Large File Handling | Limited by TCP | Limited by TCP | Optimized for large file transfers |
| Remote File Access | Unencrypted access | Secure remote file access | High-speed secure access |
| Access Controls | Basic permissions | Granular SSH-based access controls | Enterprise-grade access management |
| Transfer Files Speed (100GB) | 100+ hours international | 100+ hours international | 2.5 hours international |
| Managed File Transfer | Manual processes | Scriptable secure workflows | Enterprise automation platform |
| Best Use Case | Never – obsolete | Secure file transfers, compliance | Enterprise-scale, high-speed needs |
Critical Distinction: The difference between SFTP and FTP fundamentally comes down to encryption and data security. SFTP uses SSH protocol to create a secure connection, while FTP provides no encryption whatsoever. However, both SFTP protocol and FTP suffer identical performance limitations, which is why enterprises increasingly choose purpose-built solutions like IBM Aspera for managed file transfer at scale.
SFTP (Secure File Transfer Protocol) is a network protocol designed to transfer files securely over encrypted SSH connections. SFTP uses SSH protocol to establish a secure connection between client and server on the SFTP port (port 22), ensuring data security through comprehensive encryption. Unlike traditional file transfer methods, the SFTP protocol operates as an extension of SSH (Secure Shell), inheriting its robust security framework to protect file management operations from interception, tampering, and unauthorized access.
SFTP work begins when an FTP client initiates contact with an SSH server configured to accept SFTP connections. The SSH connection process starts with authentication, where users provide either password credentials or, more securely, SSH key pairs consisting of a private key held by the client and a corresponding public key registered on the SSH server. This SSH key authentication method provides significantly stronger data security than password-based approaches because private keys never traverse the network and cannot be compromised through brute-force attacks.
Once the secure connection is established through the SSH protocol, users can manage files through a single encrypted channel that handles all operations—file uploads, downloads, directory listings, permission changes, and file deletions. The SFTP protocol preserves file attributes including timestamps, ownership, and permissions during transfers, capabilities that standard FTP cannot provide. This makes SFTP essential for organizations requiring file management with complete fidelity, such as maintaining audit trails for compliance or ensuring backup integrity across systems.
SFTP uses SSH encryption to protect every byte transmitted through the connection. When you use SFTP to transfer files, the SSH protocol wraps all data in strong encryption before transmission. Even if network traffic is intercepted, attackers cannot decrypt file contents, authentication credentials, or SFTP commands without the appropriate SSH keys. This encryption occurs transparently to applications and users, with the SSH server and FTP client handling all cryptographic operations automatically. The result is secure file access that meets regulatory compliance requirements for data security while maintaining the straightforward file management interface users expect.
Sending files via SFTP can be accomplished through multiple approaches, each suited to different user needs and technical environments. The most accessible method uses graphical FTP client applications like FileZilla, WinSCP, or Cyberduck that support the SFTP protocol. To use SFTP through these clients, users specify the SSH server address, confirm the SFTP port (typically port 22), provide authentication credentials (username and password or path to SSH key file), and then drag-and-drop files between local and remote directories. The FTP client handles establishing the SSH connection, managing encryption, and executing SFTP file transfer operations automatically, making managed file transfer accessible to non-technical users.
Command-line SFTP work provides more flexibility and automation capabilities, particularly valuable for system administrators and developers. Linux, macOS, and Windows systems include native SFTP clients accessible through terminal interfaces. Users initiate sessions by typing sftp username@hostname, authenticating via password or SSH key, then using commands to manage files: put filename uploads local files to the remote file location, get filename downloads remote files to the local system, ls lists directory contents for file access, cd changes directories, mkdir creates new directories, and rm deletes files. This command-line approach enables scripting for scheduled backups, automated data synchronization, and integration with business workflows.
For enterprise managed file transfer requirements, organizations implement SFTP through programmatic interfaces using languages like Python, Java, or PowerShell. These scripts authenticate to the SSH server using SSH key files stored securely in credential vaults, execute predefined file management operations, implement retry logic for network interruptions, and generate detailed logs for compliance auditing. When you use SFTP programmatically, you can implement sophisticated workflows that transfer files based on triggers, apply business rules to file processing, manage access controls dynamically, and integrate secure file transfers into broader data pipeline architectures. This automation transforms SFTP from a simple file transfer tool into a comprehensive managed file transfer platform.
Organizations requiring secure file management across multiple partners often implement centralized SFTP servers where each external entity receives unique SSH key authentication credentials and isolated directory access. This architecture enables granular access controls where vendors can upload delivery files to specific directories but cannot access other organizations’ data on the same SSH server. The SFTP protocol’s built-in permission system, inherited from SSH and Unix file systems, provides the fine-grained control necessary for multi-tenant secure file access scenarios common in supply chain, healthcare, and financial services industries.
The difference between SFTP and standard FTP centers fundamentally on data security and encryption implementation. FTP (File Transfer Protocol) transmits all information—including login credentials, FTP client commands, and file contents—as unencrypted plain text over ports 20 and 21. Anyone with network access can intercept FTP traffic, view passwords, read file contents, and potentially modify data in transit without detection. SFTP uses SSH protocol to encrypt everything through a secure connection on the SFTP port (port 22), ensuring that authentication credentials, file management commands, and transferred content remain protected from eavesdropping and tampering throughout transmission.
Connection architecture provides another critical distinction when evaluating the difference between SFTP and FTP. Traditional FTP requires two separate connections: a command channel that sends instructions and a data channel that handles actual file transfers. This dual-channel design complicates firewall configuration, requires multiple port openings, and creates additional attack vectors for malicious actors. SFTP uses SSH to establish a single encrypted SSH connection for all operations—authentication, file access commands, and data transfer all flow through the same secure channel. This simplified architecture makes SFTP easier to configure securely while reducing the attack surface that security teams must monitor and protect.
Authentication mechanisms highlight another key aspect of the difference between SFTP and FTP. Standard FTP supports only username and password authentication transmitted without encryption, making credentials vulnerable to network sniffing attacks. SFTP leverages the SSH protocol’s sophisticated authentication framework, supporting both password-based and SSH key cryptographic authentication. SSH key authentication eliminates passwords entirely—the FTP client proves identity using a private key that corresponds to a public key registered on the SSH server, and this authentication occurs within the encrypted SSH connection. Organizations implementing managed file transfer with SFTP can enforce key-based authentication exclusively, eliminating password-related vulnerabilities like brute force attacks, credential stuffing, and password reuse across systems.
File management capabilities also differentiate the protocols. SFTP protocol maintains complete file attributes including timestamps, permissions, and ownership information during transfers, ensuring that remote file characteristics are preserved exactly. Standard FTP cannot reliably maintain these attributes, requiring manual correction after transfers complete. For compliance-focused organizations requiring audit trails and file integrity verification, SFTP’s metadata preservation provides essential functionality. Additionally, SFTP enables more sophisticated access controls through SSH-based permissions, allowing administrators to restrict which users can manage files in specific directories, implement read-only access for certain accounts, and audit all file access activities through SSH server logs.
A practical example of SFTP in healthcare demonstrates how organizations use SFTP for compliant managed file transfer. A medical imaging center needs to transfer large file collections containing patient MRI scans to a hospital’s radiology department while maintaining HIPAA compliance. The imaging center’s SFTP-enabled FTP client connects to the hospital’s SSH server on the SFTP port (port 22), authenticating using an SSH key that corresponds to a public key the hospital registered specifically for this imaging center. Once the secure connection is established through the SSH protocol, the technician uses SFTP file transfer commands to upload multi-gigabyte imaging files. The SSH connection encrypts every packet during transmission, ensuring data security for protected health information. The hospital’s SSH server receives these transmissions, preserves the file timestamps for medical record keeping, and applies access controls ensuring only authorized radiologists can access the remote file collections. This SFTP work flow satisfies HIPAA’s encryption requirements while enabling efficient large file transfers between healthcare facilities.
Financial services provide another compelling SFTP protocol example. A retail bank implements a managed file transfer system using SFTP to exchange transaction data with payment processors, clearinghouses, and regulatory agencies. The bank configures an SSH server that accepts SFTP connections from multiple external entities, each authenticated via unique SSH keys rather than passwords to eliminate credential theft risks. Partner organizations use SFTP to transfer files containing transaction batches, fraud reports, and reconciliation data through secure connections. The bank’s file management system automatically processes incoming files based on which SSH key was used for authentication, routing data to appropriate internal systems. When regulatory agencies request information, compliance officers use SFTP to securely upload sensitive financial reports, knowing the SSH protocol protects data security during transmission. This architecture demonstrates how organizations use SFTP for complex multi-party file access scenarios requiring both security and auditability.
E-commerce and supply chain operations illustrate SFTP in high-volume business contexts. An online retailer manages files from hundreds of suppliers who need to upload product catalogs, inventory feeds, and shipping notifications. The retailer’s SSH server implements granular access controls where each supplier’s SSH key grants access only to their designated directory on the remote file system. Suppliers use SFTP clients to connect to the SFTP port, authenticate with their SSH key, and manage files in their allocated space—uploading new product data, updating inventory levels, and retrieving order files the retailer places in their directory. The SFTP protocol’s bidirectional capability means the same secure connection serves both purposes: vendors uploading information and downloading orders. This managed file transfer approach using SFTP provides the data security required for protecting competitive business intelligence while scaling to handle transfer files from numerous partners through a single centralized SSH server.
Web developers commonly encounter SFTP when deploying websites and managing remote file systems. A development team uses SFTP to transfer files from local workstations to production web servers. Developers configure their FTP clients to use SFTP, authenticating to the SSH server via SSH keys rather than passwords. The secure connection established through the SSH protocol protects source code, database configurations, and other sensitive files during upload. The SFTP protocol’s file management commands enable developers to set proper file permissions after upload, create directory structures, and modify files directly on the remote server through the encrypted SSH connection. This SFTP work replaces insecure FTP practices that previously transmitted website code and credentials in plain text. The difference between SFTP and FTP becomes immediately apparent in this scenario—a compromised FTP connection could expose entire codebases and server credentials, while SFTP uses SSH encryption to prevent such security breaches.
Understanding the SFTP Protocol
Data Security and Encryption
Authentication and Access Controls
File Management Capabilities
Practical SFTP Implementation
The Difference Between SFTP and FTP
Real-World SFTP Examples
Performance Limitations
Enterprise Managed File Transfer Considerations
Modern High-Performance Alternatives
Strategic Implementation Guidance
Understanding SFTP enables organizations to implement secure file transfer infrastructure that protects sensitive data during transmission. SFTP uses SSH protocol to provide encryption and authentication that standard FTP completely lacks, making it essential for data security and compliance. However, the difference between SFTP and modern alternatives like IBM Aspera becomes apparent when global file transfers demand both security and speed. While SFTP provides adequate data security, organizations requiring high-performance managed file transfer should evaluate solutions that maintain encryption while eliminating TCP’s performance constraints on large file transfers across long distances.
Aside from SFTP and FTP, other solutions have been developed to fill the gaps where these more traditional data transfer services fall short. IBM’s Aspera has designed a more resilient data transfer solution that is a better fit for today’s technology-focused business.Â
IBM Aspera FASP Overview
IBM Aspera is built on the data transfer protocol FASP which is built to be up to 100x times faster than traditional FTP. Since FASP is built to perform at speed and scale where FTP falls short, Aspera can be a great solution for technology-focused organizations who are looking for faster and more reliable data transfer and collaboration capabilities.
Speed
As noted above, Aspera built on FASP is designed to be much faster than FTP or SFTP. Below we can use the following example as a good comparison between FTP and FASP.
As you work to build a more resilient, fast, and dependable data transfer and data collaboration architecture, consider the benefits of the Aspera solutions built on FASP. If you are looking to learn more about IBM Aspera, or are even interested in some training courses or material to better understand the solution consider reaching out to one of our highly capable team members here at PacGenesis.
About PacGenesis
PacGenesis is an IBM Gold-status Partner. With over 10 years of service in technology solutions, PacGenesis has supported over four hundred customers in its installation and use of leading technology-focused solutions. To learn more about PacGenesis, follow @PacGenesis on Facebook, Twitter, and LinkedIn, or go to www.pacgenesis.com.
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