How would a block be broadcasted without propagating over the network?
How would a block be broadcasted without propagating over the network? I was watching 3Blue1Brown's video over again, and the part I linked to outlines something I didn't think was possible. Let's say Alice finds a block but only wants Bob to know about it, since it includes the transaction that Alice pays Bob. So in effect, she wants to double spend. If Alice sends the block to Bob, by the protocol and the P2P aspect, wouldn't Bob broadcast the block over the network? In other words, once Alice sends the block to Bob, how is she able to prevent it from propagating throughout the entire network? http://ift.tt/2BLuGAV