Covert communication method based on Ethereum bytecode

Abstract

For communication scenarios demanding extremely high information security and facing significant risks of data leakage, a covert communication scheme based on Ethereum virtual machine bytecode was proposed. By strategically allocating the storage space of smart contract variables, the scheme embedded covert data into contract bytecode and utilized the inherent characteristics of bytecode to set positioning markers, enabling efficient extraction by the receiver. Additionally, three ciphertext parsing modes were designed to accommodate transmissions of different data scales, further enhancing the security of encoded data. Theoretical analysis and extensive experimental results demonstrate that the scheme can effectively hide up to 170 bit of information per transaction. The structural similarity of opcode frequency distributions between the embedded contract and the original contract reaches up to 99.78%. The Pearson correlation coefficient of the high-frequency 3-gram opcode patterns between the normal and embedded contracts is 0.999 7 (<italic>p </italic>= 6.42×10⁻¹⁴), indicating that the embedding process does not introduce statistically significant differences in the local instruction sequence distribution. These results fully validate the strong concealment capability, transmission efficiency, and security of the proposed scheme.