For one thing you're committing a thinko in that a hash is by definition unordered (unless you do some tie magic under the hood) so your destination is misnamed. That being said since keys and values will return things in the same order so long as you don't change the underlying hash you can swap things the obvious way.
main::(-e:1): 0
DB<1> %foo = qw( a b c d )
DB<2> @bar{ values %foo } = keys %foo
DB<3> x \%bar
0 HASH(0x7fb23c8b94b8)
'b' => 'a'
'd' => 'c'
The cake is a lie.
The cake is a lie.
The cake is a lie.