Here is example how to connect to server with PrivateKey:
Set ftp1 = New wodFtpDLXCom
Set cert = New Certificate
Set ftp1.Certificate = cert
cert.LoadKey "c:\RSAprivate.txt", "weonlydo"
ftp1.HostName = "your_hostname"
ftp1.Authentication = authCertificate
ftp1.Login = "your_login"
ftp1.Protocol = SFTP
ftp1.Connect
PublicKey is part of PrivateKey. If you wish to connect to server with PrivateKey, server need to have your PublicKey.
You can generate and save PrivateKey and PublicKey using wodCetificate component.
WodCertificate component is part of wodFtpDLX ActiveX component.