Mysterious Message From Space Leaves Clues to $1 Million Bitcoin Bounty

A Twitter user has received a mysterious message via the Blockstream satellite detailing a hunt for $1 million in Bitcoin. According to the correspondence, hunters must find 400 of 1,000 cryptographic keys to unlock the treasure.
Each of the first three keys has been hidden at four different GPS coordinates and is available to anyone who can get to the correct location. Clues to the rest will be published at a later date and will likely involve a deep knowledge of cryptography and computer scien