Miners, basically any user on the network with sufficient computing power, vie with each other to be the first to verify the new transactions and solve a cryptographic puzzle unique to that block.
The pyramid's exact size has puzzled experts for centuries, as the " more than 21 acres of hard, white casing stones" that originally covered it were removed long ago.
Everyone can grasp the significance of the puzzles posed, and if readers want to follow the genius through the steps of his solutions then Mr Bhattacharya is a clear and authoritative guide.