Smart contract gas cost optimization for pharmaceutical supply chain

Abstract

The key component of blockchain-technology is smart contract. When the predetermined circumstances are met, smart contracts on the blockchain operate automatically. For building decentralized applications Ethereum is a popular platform globally. Ether is cryptocurrency which Ethereum uses a gas, to compensate miners for their resource usage and smart contract execution. This gas cost is paid by the all the users participating in the blockchain. If smart contract is not optimized, the cost exceeds the required gas cost, leading to the excessive extra fees to the users, and this overcharging and expensive gas costs demotivate the users from using smart contracts and blockchain. Smart contracts are immutable, once deployed the code can’t be changed. This means any bugs or logical errors that appear after deployment can’t be fixed. Therefore, before deploying smart contracts onto the main chain, optimization techniques must be applied to them to make blockchain and smart contracts scalable and cost-effective. Our work contains 3 parts, (1) Designing pharmaceutical supply chain smart contract, (2) Analyzing smart contract optimization techniques, (3) Smart contract development on private chain using proof of authority as consensus mechanism on the Ethereum private blockchain and comparison of gas cost between unoptimized and optimized smart contract. We have tested our smart contract with 11 nodes on a private Ethereum blockchain and we have achieved promising results for smart contract gas cost optimization with various optimization techniques.