Assuming quantum computers were impossible, impractical, or Bitcoin soft-forked to QC resistant addresses (it's just a thought experiment).

If the aliens had mastered Q Computers the Humans would be ****** anyway lol.

I haven’t thought about aliens breaking encryption.

No idea.
But think of it this way...
If a billion alien civilizations flipped a billion quarters 256 times and generated a billion seed phrases...

Would they necessarily overlap? Statistically I think not?

 show up and think of something to use for trade, something neutral which was valuable, but small, but portable, inflation-resistant, and would go up in value the moment they said they wanted it...

That was neutral to actually trade with the Humans - why not Bitcoin?

bitcoin

Which Asset for Trade and Commerce... Would an Alien Civilization Use?

028559d218

No idea.
But think of it this way...
If a billion alien civilizations flipped a billion quarters 256 times and generated a billion seed phrases...

Would they necessarily overlap? Statistically I think not?

If the aliens *did* show up and think of something to use for trade, something neutral which was valuable, but small, but portable, inflation-resistant, and would go up in value the moment they said they wanted it...

That was neutral to actually trade with the Humans - why not Bitcoin?