There are different kinds of blockchains, which have been applied in various areas. Blockchains are relatively independent systems that are apt to form isolated data islands. Then cross-chain interaction is proposed to connect different blockchains. However, the current cross-chain methods do not maintain the security of the original blockchain. They either depend on a less secure third-party system or a less secure method. This makes the cross-chain interaction less secure than the original blockchains (the security downgrade issues), or the cross-chain interaction can be done even if the paired blockchain does not exist (the blockchain invisible issue). In this paper, we first propose a system interaction model and use it to analyze the possible security issues. Based on conclusions got from the proposed model, we propose the cross-chain method that verifies the data of the paired blockchain by the consensus algorithm of the paired blockchain (the CIFuV method). With this method, the cross-chain interaction can be as the same security as in the paired blockchain. At last, we evaluate the security issues during the system interaction process, and the possibility to have the CIFuV model on the public blockchains.

中文翻译：

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完全验证的跨链交互模型

有不同种类的区块链，它们已应用于各个领域。区块链是相对独立的系统，容易形成孤立的数据孤岛。然后提出跨链交互来连接不同的区块链。但是，目前的跨链方式并不能保持原有区块链的安全性。它们要么依赖于不太安全的第三方系统，要么依赖于不太安全的方法。这使得跨链交互的安全性低于原始区块链（安全降级问题），或者即使配对区块链不存在也可以进行跨链交互（区块链不可见问题）。在本文中，我们首先提出了一个系统交互模型，并用它来分析可能存在的安全问题。根据提出的模型得出的结论，我们提出了通过配对区块链的共识算法（CIFuV方法）验证配对区块链数据的跨链方法。通过这种方式，跨链交互可以像配对区块链一样安全。最后，我们评估了系统交互过程中的安全问题，以及在公共区块链上使用 CIFuV 模型的可能性。