Review my site: SecretShare.net - Stop sharing passwords in emails & chat
secretshare.net
secretshare.net
Perhaps you can keep it much simpler and have a link to technical details at the bottom. Many people probably don't know what "Encrypt client side" or Expires in x actually means. To that end you might want a really simple 3 step explanation of how to use it.
Or maybe you could have an "Advanced" mode with these options.