Blockchain essentially is in the form of spreadsheet that is accessible to all, but not editable for everyone. Each piece of information is protected by a code. Blockchain can be used to protect Internet-of-Things (IoT). In these days of hacking, there are concerns about IoT. The systems are so vulnerable that if a hacker is to get access to even one of the devices, the whole net-work could be brought down . Blockchain can eliminate this uncertainty about IoT devices. As each block is protected by a separate code, even if the hacker has access to one block, the other mechanisms remain secure. Thus the chain is protected. This is useful in healthcare industry too. Blockchain can limit the extent of hacking. It is useful in managing public utilities.