> If I have a private key to my coins, why is someone else allowed to disallow a transfer of them? They are allowed to try, but no single entity can completely

> If I have a private key to my coins, why is someone else allowed to disallow a transfer of them? They are allowed to try, but no single entity can completely block a valid transaction from being confirmed. The legitimate reason they may do so is because they believe you are trying to double (or N) spend the transaction, and they have chosen a conflicting transaction instead, likely the first one they saw. > Why is Bitcoin made up of back-links to previous blocks? Blocks are a way to get everyone on the same page, when a new block is found everyone is now working on top of the same history. The reason to use ~10 minute blocks of transactions instead of 2 second blocks or even updating on every new transaction is to avoid a constant stream of conflicting states arriving from different parts of the world, which would increase the necessary communication between nodes. > If at any point they did not have all of the transaction(which means if anyone else has reported a transaction that they have disallowed, easily compared by simply checking every miners head hash), they are considered to be offline and do not receive a mining share. In that case if I'm a miner I can just create a transaction that I share with no one, include it in my block, broadcast the block and now all other miners are considered offline because their blocks didn't include my transaction and I get 100% of the reward.