Table 9.

Some examples of cloud-related solutions

Publication	Contribution	Description
Hwang et al. [42]	Automatic indemnification mechanism	It is based on smart contracts for refunding cloud storage service clients when the service provider violates the service level agreement by raising objections to a smart contract.
Scoca et al. [84]	Smart contract negotiation	It is an autonomous negotiation of smart contracts in cloud computing, which analyses the cost and the necessary changes for reaching an agreement. It is based on a formal language that specifies interactions between offers and requests.
Wang et al. [98]	QoS-Aware service composition	It is a smart-contract based algorithm for constructing cloud service-based systems through the composition of existing services.
Zhou et al. [118]	Cloud SLA enforcement	It is a witness model to credibly enforce the cloud service level agreement (SLA) using the witness role based on blockchain and smart contracts to solve the trust issues about who can detect the service violation and how the violation is confirmed.