The traditional covert communication that relies on a central node is vulnerable to detection and attack. Applying blockchain to covert communication can improve the channel's anti‐interference and antitampering. Whisper is the communication protocol of Ethereum, which mainly relies on payload to store information and padding to expand. These two fields can store a large amount of information, creating conditions for the realization of covert communication. In this paper, we propose a covert communication method based on the whisper protocol to covertly transfer information in the blockchain. To implement this method, we use payload to store the carrier information, matching it with the secret message. The generated index is recorded in the padding field. To improve the concealment of communication, we simulate the default filling rules of the protocol to maintain the message size. A new topic–key pair interaction method is also proposed to improve the security of the model. Moreover, the anti‐interference, antitampering and antidetection of the newly proposed model are verified through theoretical analysis and experiment. The experimental findings show that the amount of information in the proposed method is 4.7 times that of the traditional time‐based covert communication. The time consumption of information transmission is reduced to 52.25% under the same settings and even less in actual use. The cost of the new topic–key pair interaction is reduced by nearly 50% compared with the original method.

中文翻译：

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一种基于以太坊耳语协议的区块链隐蔽通信方法

依赖中心节点的传统隐蔽通信容易受到检测和攻击。将区块链应用于隐蔽通信可以提高信道的抗干扰和抗篡改能力。Whisper是以太坊的通信协议，主要依靠payload来存储信息和padding来扩展。这两个字段可以存储大量信息，为实现隐蔽通信创造了条件。在本文中，我们提出了一种基于耳语协议的隐蔽通信方法，以在区块链中隐蔽传输信息。为了实现这种方法，我们使用有效载荷来存储运营商信息，将其与秘密消息进行匹配。生成的索引记录在填充字段中。为了提高通信的隐蔽性，我们模拟协议的默认填充规则来保持消息大小。还提出了一种新的主​​题-密钥对交互方法来提高模型的安全性。此外，通过理论分析和实验验证了新提出的模型的抗干扰、抗篡改和抗检测能力。实验结果表明，该方法的信息量是传统基于时间的隐蔽通信的4.7倍。相同设置下，信息传输的时间消耗降低到52.25%，实际使用中更少。与原始方法相比，新的主题-密钥对交互的成本降低了近 50%。通过理论分析和实验验证了新提出模型的抗干扰、抗篡改和抗检测能力。实验结果表明，该方法的信息量是传统基于时间的隐蔽通信的4.7倍。相同设置下，信息传输的时间消耗降低到52.25%，实际使用中更少。与原始方法相比，新的主题-密钥对交互的成本降低了近 50%。通过理论分析和实验验证了新提出模型的抗干扰、抗篡改和抗检测能力。实验结果表明，该方法的信息量是传统基于时间的隐蔽通信的4.7倍。相同设置下，信息传输的时间消耗降低到52.25%，实际使用中更少。与原始方法相比，新的主题-密钥对交互的成本降低了近 50%。相同设置下，信息传输的时间消耗降低到52.25%，实际使用中更少。与原始方法相比，新的主题-密钥对交互的成本降低了近 50%。相同设置下，信息传输的时间消耗降低到52.25%，实际使用中更少。与原始方法相比，新的主题-密钥对交互的成本降低了近 50%。