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Blockchain for IoT Security

• RPL routing attack.

• Sinkhole and wormhole attacks.

• Sybil attacks on intermediate layers.

• Authentication and secure communication.

• End-to-end transport level security.

• Session establishment and resumption.

• Privacy violations.

4.5.3  High-level Security Issues

The high-level security issues are the security concerns related to the applications

executing on IoT as described later. The key high level issues are:

Insecure interfaces.

Insecure software/firmware.

Middleware security.

4.6  BLOCKCHAIN

Blockchain contains a sequence of cryptographically interconnected blocks

(Makhdoom et  al. 2019). Bitcoin is one of the most popular implementations of

blockchain. Figure 4.1 shows an example of a blockchain, where each chain con­

sists of multiple transactions. The validation of the blocks is based on cryptographic

means. Each block has the hash value of the preceding block, which includes a nonce

(a random value). This entire system establishes a trust model where each node vali­

dates the other nodes and does not require a central authority to validate them.

4.7  BLOCKCHAIN AND IOT

IoT has multiple security challenges that can be overcome using the benefits that the

blockchain technology offers. Blockchain provides a unique way to establish trust

relationships and immutability of data. IoT’s distributed and heterogeneous archi­

tecture also stands to benefit from blockchain’s decentralized architecture. Hence,

blockchain could be one of the solutions to address the security challenges being

faced by IoTs today.

FIGURE 4.1  Blockchain containing a continuous sequence of blocks.