AEchain: A Lightweight Blockchain for IoT Applications

IoT nodes comprise of sensors and embedded resource-constrained systems. On the other hand, blockchain is regarded as computationally expensive due to the consensus algorithms. Therefore, it is challenging to apply blockchain to an IoT system. This work presents a unique concept that integrates blockchain with lightweight cryptographic solutions targeting resource-constrained IoT sensor nodes. In particular, proof-of-authentication utilizing a lightweight authenticated encryption (AE) scheme to achieve consensus is proposed. At sensor nodes, a tag is generated based on sensor data, which is then broadcast to the network. Upon authentication from the cluster head node (e.g., a gateway), the block is hashed using the lightweight hash function and added to the blockchain. The proposed solution can be implemented in software (e.g., microcontroller) or hardware platform (e.g., FPGA, ASIC). Experimental results show that lightweight authentication can perform 1.34 M authentications per-second with only 6.55 k lookup tables (LUTs) on the Spartan-6 FPGA platform. This high-throughput authentication can speed up the consensus in blockchain, utilizing few resources and making it very suitable for applications in IoT sensor nodes.