Backups
What is SFTP, and when should you use it?
SFTP is the SSH File Transfer Protocol. It uses the SSH transport to move and manage files securely, which makes it useful for server administration, website transfers, automated jobs, and backup destinations.
SFTP is not FTP with an S added
FTP, FTPS and SFTP are different protocols. SFTP runs over SSH and commonly uses the same server-side SSH service and authentication mechanisms. FTPS is FTP protected with TLS.
Password or SSH key authentication
SFTP can use passwords, SSH keys, or other SSH-supported authentication depending on the server policy. Automated backup jobs often benefit from dedicated keys because the job does not need to store a reusable interactive password.
A file-transfer account does not need a shell
A well-designed SFTP service can restrict an account to file transfer, constrain it to a specific directory tree, and disable interactive shells or forwarding features that the customer does not need.
Use a separate identity for automation
Do not reuse a personal administrator key for every automated backup job. Give each service its own credential, limit what it can access, and make revocation possible without disrupting unrelated systems.
Test restores, not just uploads
A successful SFTP transfer only proves that bytes reached the destination. Periodically download representative data, verify integrity, and prove the backup process can restore what the application actually needs.