It is best to assume that the government organizations who may or not have information or proof of alien existence and technology are really just to ignorant and war mongering mindset biased to not really have anything of value.
Many people want to believe in some government conspiracy regarding UFO and alien life and technology. Though it is reasonable to think they likely have some knowledge and proof, its really quite clear that they do not have the intelligence or proper mindset to really do anything more with it than hide it for fear of others finding out how ignorant they are.
But don't we already know this?
Who is fooling who here?
There is nothing we are going to get from any intelligent life above ourselves, that we can actually properly use. We can however develop our own technology such that we actually understand it.
How I know this and am very certain of is really quite simple.
The description of "arch of the covenant" is so detailed that we can and always have been able to build it. A project to do such a thing was undertaken by Maryland Institute of Technology. The project was canceled as it began to put off such a high level of static electricity that it became dangerous for the students building it. You will not find reference to this project online, or at least I couldn't find it. It was before there was a WWW.
The point is, why look for the Arch of the Covenant and pursue all the mystery/history of it, when we have the plans to build it?
There is more to this.
If we can figure out how to convert static electricity to something more stable, then perhaps we have free energy.
There is more:
If we cannot build this in a safe manner, given all our technology of today............ what does that say about our evolution or possible alien life and technology? Are we de-evolving? Or was there more to the building of the Arch, such as alien influence and help in the construction?
This is not knowledge or technology that is being hidden, but rather information that has been spread around the world with full public access.
So why is it that I do not believe governments have any information of any usable value other than keeping it hidden to hide their ignorance, if there is anything there at all?