# CAR-Tourist: An Integrity-Preserved Collaborative Augmented Reality Framework-Tourism as a Use-Case
## 4 Implementation  
This section provides implementation details of the proposed solution by first providing details of the implementation of the proposed application in Hyper-ledger Fabric, including details of its components and the reason for choosing Hyper-ledger Fabric  
Figure 4: Integrity aware real example of Collaborative AR with Blockchain. (other platforms are also available, details of which are provided in the following paragraphs). Later, the study presents the results of the performance analysis of Hyper-ledger Fabric implementation. IBM Blockchain: A permission blockchain network ensures tighter control over access, which is one of the main reasons for using this platform for business applications. However, there are some issues reported on this platform, which are as follows: there is no support for configuring an external certificate authority (CA), the IBM Kibana interface by default shows the logs of the past 30 days' activities, chaincode container hangs sometimes, and there are issues related to chaincode installation [46]. R3 Corda: R3 Corda [47] is a distributed ledger platform designed for managing financial records by the company R3. The main purpose of Corda is to replace software used for financial transactions with a shared trusted ledger. Corda was designed to resolve issues such as privacy and scalability of blockchain applications; however, some large companies have observed implementation constraints and thus it is not suitable for our use case. HydraChain: Hydrochain blockchain platform [48] supports the development of the permission distributed ledger. This technology is extended from Ethereum; therefore, the tools for developing smart contracts and decentralized apps can be exploited; however, it also inherits issues from Ethereum. Quorum: Quorum [49] is an extension from the Ethereum code base to provide a permission blockchain platform that supports confidentiality and privacy for all transactions using the smart contract. Authors in [49], studied the performance evaluation of Quorum smart contracts and various transactions in terms of latency, throughput, and their effects on blockchain application design. Quorum has lower throughput at higher load and experimental results suggest an increase in transaction latency concerning reading and writing operations. IOTA: IOTA [50] is a blockchain platform designed specifically for IoT blockchain applications using DAG (Directed Acyclic Graph). In [51], authors have evaluated the performance of various blockchain platforms wherein it is suggested IOTA applications are scalable because of the DAG structure of transactions. BigChainDB and MultiChain: BigchainDB [51] is a scalable decentralized database used by various blockchain applications including IOTA. For example, BigchainDB is used to create a product database for IoT devices for blockchain applications to maintain the historical record of provenance and ownership of devices. Similarly, another blockchain platform called Multichain [52] was initially developed to maintain ownership and transfer of assets on blockchain applications. Some developers have noticed high latency and response time while testing multichain with Azure VM. Hyperledger Fabric [53]: provides an open-source platform to implement permission blockchain applications. It is the most used and appealing permission blockchain platform and offers various features, such as an open-source permission blockchain platform, the capability of integration with other platforms (IOTA), generalized, adaptable by different industries, consensus finality, high throughput, and effective smart contracts. These prominent features motivate us to select Hyper-ledger Fabric for the implementation of our proposed Collaborative AR module. In the following subsections, different components of the Hyper-ledger are elaborated upon along with other blockchain components in terms of tourist guides and the Collaborative AR proposed module. All the transactions are implemented over the smart contract.