Transferring files securely.
PLAIN FTP
Sends your username and password unencrypted. Anyone on the network path can read them. Do not use it.
FTP OVER TLS
Standard FTP with encryption added, using the server's certificate. Most FTP clients support it; select FTPS or "Require explicit FTP over TLS" in the connection settings.
SFTP
A different protocol entirely, running over SSH. Encrypted by design. Available where your account has SSH access.
WHICH TO USE
SFTP where available, FTP over TLS otherwise. Never plain FTP.
CERTIFICATE WARNINGS ON CONNECT
Your FTP client may warn about the certificate, particularly if connecting by server hostname rather than domain. Verify it matches the expected server before accepting.
IN FILEZILLA
Set the encryption option to "Require explicit FTP over TLS" in the site settings. Accept the certificate once after verifying it.
A SECURITY NOTE
FileZilla stores saved passwords in a file that malware specifically targets. Use a master password, or do not save passwords.
