The last section tells that you need to transmit classical information to make sense of entangled particle measurement. Entanglement serves as a secure channel.

The last section tells that you need to transmit classical information to make sense of entangled particle measurement. Entanglement serves as a secure channel. If you have two entangled coins, you know that the second coin came up heads, if your coin came up tails. You can't transmit information that way, because if you'll force your coin to land heads, you'll break entanglement. But you can use the results of coin flips as a cipher.