- Blockchain can add value to IoT deployments in the security domain:
- Immutability of data: Blockchain keeps the data honest – when data a blockchain ledger is updated with a transaction no one can change it.
- Immutablity of identity: “Blockchains can give a device an immutable, globally-verifiable digital identity, which is step 0 of deploying secure systems at scale. If you can’t guarantee identity, cryptographically-speaking, then all other requirements (discovery, communication, etc.) are vulnerable to MITM and Sybil attacks.” 
- Decenetralisation of security oversight: Blockchain eliminates the reliance on trusted third parties like certificate authorities and domain registries.
Furthermore, decentralised IoT applications could use blockchain to enable collaboration among connected devices (e.g. share computing power or data)
With IoT, security is a major challenge. Blockchain technology is the missing link to secured communication in IoT.
By adding Blockchain, we can have a secured mesh network that will allow IoT devices to interconnect reliably and avoid the threats that are prevalent in central server models. This decentralized approach would eliminate the single point of failure, creating a more resilient ecosystem for devices to run on. The cryptographic algorithm in Blockchain would make data more private.
These capabilities make Blockchain a fundamental element of IoT solutions. It is not a surprise that enterprise IoT Technologies have become one of the early adopters of trust technologies.