Encrypted or unencrypted on VLAN Attachment

[Thomasaw]

Hi, everyone

I have a question:
Which should I select 'encrypted' or 'unencrypted' when I deploy VLAN Attachment with Cloud Interconnect?

Also I referred a document below, but I don't make sense.
https://cloud.google.com/network-connectivity/docs/interconnect/how-to/partner/creating-vlan-attachm...
That shows how different that VLAN Attatnment works, but at a point of designing, it is not enough for me.

I hope someone to have a good knowledge about it and share with us.

regards,