Still looking for the solution
Working Solution 2017/07
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys D46F45428842CE5E
Solution
gpg --keyserver hkp://subkeys.pgp.net --recv-keys D46F45428842CE5E
gpg: requesting key 8842CE5E from hkp server subkeys.pgp.net
gpg: keyserver timed out
gpg: keyserver........