title: lftp with key + passphrase
body: <p>I'm using <strong>lftp</strong> to send files to an SFTP server, but I don't how to connect with key and passphrase.</p>
  <p>So in <code>sftp</code>, I can do this:</p>
  <pre><code>sftp -i .ssh/id_rsa.mykey login@my.host.fr
  Enter passphrase for key '.ssh/id_rsa.mykey': my passphrase here
  </code></pre>
  <p>So, how can I use lftp with this connection method?</p>