Creating encrypted backup for esx 5 VM

Hi

I have a esxi 5.0.0 host running 4 virtual machines. I wanted to create backup's of the VM's, encrypt them and transfer them to a outside server which will hold this esxi VM backups.

Until now in the esxi console i have not found any command which will encrypt or compress(zip) with password the datastore files containing VM files to run. My backup will be done while the VM is shutdown.

How do i install such tools/application on the esxi. Any other open source option will appreciated.

I'm also viewing vSphere Management Assistant (vMA) but if have not found any way to perform what I'm searching for.

Thanks,

Edmond.