[U-Boot] password for u-boot

[necib yassine]

Hi everyone,
I have a technical question about u-boot.
Is there any way to set up a security (for instance password...) either any
users cannot handle u-boot environments variables ?
When the user plug his serial sâble, I do not want to allow him to see any
the contents variable envrionments.
I found something about CONFIG_ENV_AES but it is no clear about what the
user can/cannot do.
http://events.linuxfoundation.org/sites/events/files/slides/elce-2014.pdf
Thank you :)


-- 
NECIB Yassine