Research on a network covert channel based on blockchain

Covert channel refers to the channel where malicious communication parties encode and transmit information by modifying the value, characteristics or status of shared resources. With the birth of blockchain technology serving Bitcoin, its characteristics of decentralization, anonymity and non tamper make blockchain as a covert communication carrier superior to traditional networks, databases and operating systems. We summarized the development process of covert channels, and compared traditional network covert channels with blockchain based network covert channels. The blockchain network covert channels are divided into four types: transaction address type, smart contract type, signature algorithm type and P2P broadcast mechanism type, and the modeling definitions are given. Three evaluation indexes are proposed for the concealment, transmission efficiency and communication cost of the hidden channel in the blockchain network.