  In most websites, the online rating system provides the ratings of products
and services to users. Lack of trust in data integrity and its manipulation has
hindered fulfilling user satisfaction. Since existing online rating systems
deal with a central server, all rating data is stored on the central server.
Therefore, all rating data can be removed, modified, and manipulated by the
system manager to change the ratings in favor of the service or product
provider. In this paper, an online rating system using distributed ledger
technologies has been presented as the proposed system to solve all the
weaknesses of current systems. Distributed ledger technologies are completely
decentralized and there is no centralization on them by any institution.
Distributed ledger technologies have different variants. Among distributed
ledger technologies, blockchain technology has been used in the proposed rating
system because of its support for smart contracts. In the proposed online
rating system, the Ethereum platform has been chosen from different blockchain
platforms that have a public permission network. In this system, the raters
cannot rate unless they submit a request to the system and be authorized to
take part in the online product rating process. The important feature of the
Ethereum platform is its support for smart contracts, which can be used to
write the rating contract in the Solidity language. Also, using Proof of
Authority consensus mechanisms, all rating transactions are approved by the
surveyors. Since in the real Ethereum system, each rating transaction is sent
to the network by the raters, some gas must be paid for each rating
transaction. However, since this method is expensive, TestNet blockchain can be
used in the rating system. Finally, the proposed rating system was used for
rating the restaurants of a website and its features were tested.
