/usr/lib/x86_64-linux-gnu/libdhash.so is in libdhash-dev 0.6.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libdhash.so.1.1.0
/usr/lib/x86_64-linux-gnu/libdhash.so.1.1.0