The correct way to do this would be using OP_RETURN imo. This special opcode is meant for committing to data like this. So for example one could commit to 4 byt

The correct way to do this would be using OP_RETURN imo. This special opcode is meant for committing to data like this. So for example one could commit to 4 bytes representing the IP address. To ensure that only authorized parties can update the IP the client should only accept transactions that were sent from a certain address, meaning they are automatically signed with the authorized-party's key. Definitely an interesting use case for BTC to route around such censorship.