bitcoin core – What stops somebody from tampering with node software program and therefore would have the ability to disrupt the blockchain?

You might be appropriate, when the brand new block is broadcasted, all the opposite nodes would reject it if it does not observe the consensus guidelines, wouldn’t add it to the blockchain nor will they transmit it.

In actual fact, the “software program” itself will not be vital (there are a number of Bitcoin node shoppers), similar to many software program items can create JPEG photographs (ranging out of your cellphone, laptop, digicam, and so forth.), the protocol itself relies on what the nodes agree on.

You’d be basically creating a tough fork, and if for any motive all of the nodes and miners use your “re-written software program”, and is accepted by everybody, then at that time that new Bitcoin in all probability turns into… Bitcoin.