Blockchain Meets Covert Communication: A Survey
Zhuo Chen, Liehuang Zhu, Peng Jiang, Can Zhang, Feng Gao, Jialing He, Dawei Xu, Yan Zhang
Abstract
Covert communication enables covert information transmission in an undetectable way to prevent the exposure of communication behaviors. Blockchain-based covert communication breaks through the limitations on concealment, reliability and anti-traceability, and has shown promising application prospects in both sensitive data transmission and botnets. Although there are studies on blockchain-based covert communication, it still lacks a systematic investigation. In this paper, we conduct a comprehensive study on channel building and survey its core technologies by information embedding, transaction filtering, and transaction obfuscation. We also summarize evaluation metrics to better analyze blockchain-based covert channels. Privacy aspects are also discussed. Finally, we suggest seven future directions to stir research efforts into this area.