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Lately there’s a lot of talk about blockchain usage in IoT world, so I decided to investigate what’s it all about and in this post I’ll share with you some of my findings.

First of all, what is a blockchain?  Blockchain is a list of data records called blocks, each of them contains a cryptographic hash of a previous one, then timestamp and transaction data. Blockchain is design in a way that data records in a any block can’t be modified afterwards without modifying all the linked blocks and also there’s a anonymous peer 2 peer network community taking care for blocks validation and inter-node communication. Or to explain it in simple words, you ask  all the peers the same question, you should get the same answer from all of them, if someone is lying, he would be expelled and all the others would be informed about it. Blockchain became popular because of the bitcoin, a cryptocurrency invented by “Satoshi Nakamoto” – whoever it might be. Anyhow, now we see blockchain used for many applications and thus we have it in IoT world as well.

For what for to use blockchain in IoT world? Applications are numerous: IoT device ID validation, creation of distributed data, selling of collected data – just to name a few possibilities, but as you can imagine they are all engaged around security. Even though  blockchain offer mass of opportunities, there are many problems when we decided to combine these two infant technologies. IoT needs to offer CIA (confidentiality, integrity and availability) and scalability for up to 10 years and on the other hand we have blockchain that’s “a bit unpredictable” since system is volatile and speculative. For sure we can skip over that threat by creating our own private blockchain – but for this you need a lot of time and money. Then there’s a another big problem, blockchain’s security depends on its cryptography and this is created by people who are not immune to mistakes – as it happen with IOTA. You’d be better of with existing strong encryption when it comes to confidentiality. Strong point of blockchain usage in IoT would definitely be integrity, so we’d be sure that we are getting the data from and sending to the correct end device that’s somewhere out in the public. Regarding the availability, even though blockchain offer self healing process if some end device is taken off the network, we need to be aware of the latency it can cause and this is a big issue for IoT application. IOTA is tackling this latency issue with its variation of a blockchain called DAG (directed acyclic graph) “Tangle”.    

Well even though opinions are divided and it seems that there are more cons than pros when it comes to blockchain usage in IoT world, I’d bet that at the end we’ll see it a lot – also, for  me it will be interesting to reflect on this prediction in a few years.