While FTP is the traditional file transfer protocol, SFTP (Secure File Transfer Protocol) is an alternative to FTP that allows you to transfer files by adding a layer of security to the process. SFTP uses SSH (secure shell) encryption to protect the data being transferred. Show
SFTP vs FTPWith SFTP, the data that moves between your FTP client and your web server is encrypted. Thus, your connection with SFTP is always secured. This means that there will be no interception attacks on your data since everything you transfer is always encrypted. On the other hand, username and password authentication are required when you initially connect with FTP, but this doesn't guarantee the safety of your data between your web server and your FTP client since it is not encrypted. Both protocols enable you to move files between your FTP client and web server, but to sum it up, SFTP is more secured than FTP. Back to top. How to Connect to SFTP Using FileZilla?
Back to top. How to Upload Files Using FileZilla?
Back to top. How to Download Files Using FileZilla?
Note: Click on the root folder ("/") if you wish to download all files on the server. Otherwise, select the subfolder or the files you intend to back up. Back to top. What Other FTP Clients Could I Use?Here are a few options for you to consider:
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Get this webpage as an eBook for offline viewing!Defining Secure File Transfer ProtocolSFTP stands for SSH File Transfer Protocol or Secure File Transfer Protocol. It is used to secure file transfers between a remote host server and a client user over a public network like the internet. SFTP ensures that the host and client are validated and authenticated. Important Facts about SFTPSFTP works in a client-server architecture. Clients always initiate a request to connect and servers passively listen for client requests.
SFTP Uses SSHWhat Is SSH?Secure shell (SSH) encrypts identities, passwords and other transmitted data to protect it from theft or tampering by unauthorized entities. Its default port is port 22. SSH refers to
What Is OpenSSH?OpenSSH is an open-source implementation of the SSH protocol. SSH1 protocol support is disabled by default. OpenSSH is integrated into base operating systems such as Microsoft and Linux Red Hat. SSH1 versus SSH2* SSH1 and SSH2 are not compatible with each other. SSH1
SSH2
An SSH Key AnalogySSH uses keys to authenticate both participants. To understand how SSH keys work, refer to the following analogy. Jack wants to send a confidential message to his colleague Jill. He needs to verify it is really Jill before he sends the actual message. 1. Jack locks message in a box and sends it to Jill’s saved address. 2. Jill receives the box. To verify it is really from Jack, she puts her own lock on the box and sends it to his saved address. 3. Jack recognizes his own lock and Jill’s signature lock. He removes his lock and sends it back to her. 4. Jill receives the box and sees that Jack has removed his lock, so she knows he received it. She removes her own lock to read the secret message. SFTP in the TCP/IP ModelNow with an understanding of how SSH keys work, let’s look at how SFTP interacts with other layers of a network. The file transfer process spans multiple layers of a network. When discussing how SFTP works, it is important to understand how it fits into the Transport Control Protocol/Internet Protocol (TCP/IP) model. The TCP/IP model helps determine how a computer should be connected to the internet and how data should be transmitted. It is organized into four layers:
SFTP in TCP/IP ModelAs a protocol, SFTP lives in the application layer. It uses TCP in the transport layer to execute the TCP handshake and establish a connection across the internet and network layers. Then, it secures the channel so the messages and data traveling across networks are encrypted. Knowing what layers run underneath SFTP will help with understanding how SFTP works in the next section. How SFTP Works1. User CommandThe user runs a command to open the SSH connection. SFTP can manipulate data remotely to copy files, delete files, etc. This can be done with SFTP commands. To get a list of available SFTP commands, simply type help or ?. sftp> help
2. TCP HandshakeBefore an SFTP file transfer happens, the client and server verify the connection via a three-way TCP handshake. TCP is a connection-oriented protocol, which means that both computers verify a connection before files are sent. The handshake occurs in a series of messages between the parties to confirm that they both have access to the correct port in the transport layer (port 22). If data does not arrive after the handshake is complete, TCP will make sure that it is re-sent. 3. Authentication & EncryptionCredentials are created and shared between parties. The credentials validate the server, negotiate a session key and authenticate the client. The most secure option is for the host server to generate a user and password for the client and for both to create SSH private/public key pairs.
Authentication Steps1. The client verifies the server’s identity.
Public Key CryptographyHow Does It Work? Public keys can:
Private keys can:
* The private key should never be shared because it compromises file transfer security. 2. Both parties negotiate a session key using the Diffie-Hellman algorithm. The session key encrypts the entire session. The Diffie-Hellman algorithm makes it possible for each party to combine their own private key and the public key from the other system to make an identical secret session key. The key pairs used to create the session key are separate from the SSH keys used to validate and authenticate the client and server. How the Diffie-Hellman Protocol WorksIn the Diffie-Hellman key exchange scheme, the key pairs created by the parties can be used to compute a shared secret offline. The shared secret can be used as the key for a symmetric cipher. Diffie-Hellman is the basis for many authenticated protocols. It provides forward secrecy in Transport Layer Security’s ephemeral modes. What Perfect Forward Secrecy (PFS) Means
3. The server authenticates the client using an SSH key pair. This pair consists of a public key and a private key. Here is how that works:
4. File Is Transferred
Finally, the file is transferred over the encrypted channel in packets. Each packet has some of the data being transferred. At the receiving end, the packets are put back together into the original file. Relying just on SFTP alone may be adequate for some file transfer use cases, however, sensitive, business-critical file transactions require additional enterprise-grade protection, control and visibility. SFTP servers do not have all the security features necessary for compliance with GDPR and other regulations or governance policies. A managed file transfer (MFT) solution enhances secure file sharing by providing this required functionality. MFT is a file transfer system that utilizes multiple protocols, including SFTP, and is able to act as a client or server to enable push or pull connectivity between the MFT solution and its endpoints. Readily available capabilities of MFT include comprehensive end-to-end security; granular tracking, logging and retention settings; and high availability and disaster recovery (HADR). Learn more about the added security and visibility of MFT » Frequently Asked Questions about SFTPWhat is an SFTP client?An SFTP client is any software that can connect to an SFTP server. A client is used to upload or download files to the server. Clients typically have lower processing power and less resources than servers. They always request information from servers. Popular SFTP clients include Solar-PuTTY, WinSCP, FileZilla and CyberDuck. What is an SFTP server?An SFTP server is a repository where files are stored. Servers have higher processing power and more resources than clients. They respond to clients with requested information. What are the benefits of SFTP?Security is the biggest benefit of SFTP. Because usernames, passwords and data are all encrypted in transit, no one can intercept and read the data. Other benefits of SFTP include
What is SFTP used for?SFTP is used across many different industries and in a variety of situations, such as
Although SFTP is being used in these scenarios, adopting a managed file transfer solution adds reliability and visibility to sensitive, business-critical file transactions. MFT software provides centralized control to simplify configuration and to monitor / audit file transfers to meet compliance requirements and governance policies. How fast is SFTP?SFTP file transfers are typically 1-1.4 Mb/second, according to N Software. This is a bit slower than FTP transfers for two reasons:
To speed up file transfers more, businesses can invest in a high speed managed file transfer service. What is the difference between SFTP and SSH?SFTP and SSH are both protocols, but SFTP runs over the SSH protocol. On its own, SSH cannot transfer files – it can only create a secure connection. Users can perform certain actions with files if using SFTP but cannot do those actions with SSH, such as
How secure is SFTP? Is it more secure than FTPS?SFTP is very secure because the connection always begins as encrypted. SFTP is more secure than FTPS because FTPS connections begin in an unencrypted state. What are the differences between SFTP and FTPS?
What are the differences between SFTP and SCP?SFTP and Secure Copy Protocol (SCP) both use the SSH protocol for authentication, meaning they are equal in security. However, SCP can only transfer data, not manage it. SCP is typically faster than SFTP because it does not acknowledge packets like SFTP. Unlike SFTP, SCP cannot
Additionally, unlike SFTP, SCP does not have a graphical user interface (GUI). SourcesResourcesGet this webpage as an eBook for offline viewing!Questions?If you have questions about SFTP and secure file transfer, we can help.What is the three or four letter identifier found at the end of a file name that follows a period called?A file extension is a three- or four-letter identifier found at the end of a file name and following a period. These extensions tell you about the characteristics of a file and its use.
What works in conjunction with a Secure Sockets Layer to ensure that data is transported safely?Hypertext Transfer Protocol Secure (https) is a combination of the Hypertext Transfer Protocol (HTTP) with the Secure Socket Layer (SSL)/Transport Layer Security (TLS) protocol. TLS is an authentication and security protocol widely implemented in browsers and Web servers.
What does the S at the end of FTPS?FTPS: The “S” Means SSL or Secure Sockets Layer
SSL, or Secure Sockets Layer, is a cryptographic protocol. (Now it's known as Transport Layer Security (TLS), but that screws up our acronym, so just know that the terms are typically interchangeable, even though TLS is what is used today.)
What term is used for 2 or more PCS that are connected and share resources?A network consists of two or more computers that are linked in order to share resources (such as printers and CDs), exchange files, or allow electronic communications.
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