Attacks Against Cross-Chain Systems and Defense Approaches: A Contemporary Survey
Li Duan, Yangyang Sun, Wei Ni, Weiping Ding, Jiqiang Liu, Wei Wang
Abstract
The blockchain cross-chain is a significant technology for inter-chain interconnection and value transfer among different blockchain networks. Cross-chain overcomes the “information island” problem of the closed blockchain network and is increasingly applied to multiple critical areas such as finance and the internet of things (IoT). Blockchain can be divided into three main categories of blockchain networks: public blockchains, private blockchains, and consortium blockchains. However, there are differences in block structures, consensus mechanisms, and complex working mechanisms among heterogeneous blockchains. The fragility of the cross-chain system itself makes the cross-chain system face some potential security and privacy threats. This paper discusses security defects on the cross-chain implementation mechanism, and discusses the impact of the structural features of blockchain networks on cross-chain security. In terms of cross-chain intercommunication, a cross-chain attack can be divided into a multi-chain combination attack, native chain attack, and inter-chain attack diffusion. Then various security threats and attack paths faced by the cross-chain system are analyzed. At last, the corresponding security defense methods of cross-chain security threats and future research directions for cross-chain applications are put forward.