Research On Covert Communication Technology Based On Blockchain

In the information age and internet times at present,network security and secure network communication are becoming more and more important.However,there are shortcomings such as easy detection and exposure in the covert communication technology under the traditional network,along with the mature detection technology of the traditional covert channel,which makes it difficult to meet the needs of covert communication.The characteristics of decentralization,anonymity,and immutability of blockchain technology make blockchain become a natural public data platform and public infrastructure,and it is easy to be used as an information carrier for secret communication under the cover of legal transactions.Due to the special mechanism of the blockchain,some blockchain covert communication schemes have problems such as weak concealment of secret information,cumbersome identification and screening of confidential transactions,poor usability and low comprehensive performance.Because of the above problems,the thesis conducts an in-depth study of the related literature on blockchain-based covert communication.Through the summary and analysis,a new covert communication scheme in the blockchain network environment is proposed and designed,which solves some of the existing problems and can safely build a covert channel for covert communication in the blockchain network.The main work is as follows:(1)Combined with the system characteristics of the blockchain and the existing covert communication schemes,a general model of covert communication under the blockchain network environment is constructed,and the covert communication under the blockchain network environment is compared with the covert communication under the traditional network.Communications were compared.The key issues involved in the three main steps of covert communication in the blockchain environment are summarized and analyzed.(2)A covert communication scheme based on blockchain transaction mechanism is designed.In the blockchain,the normal transaction is used as a mask,and the address generation mechanism is used to embed the secret information in the public key hash field;combined with the hash algorithm,a new key update mechanism is proposed,and a covert channel is constructed.It can realize the update of the channel and avoid address multiplexing;using the bitcoin anti-double-spending mechanism,it solves the problem of paying to the fake public key hash method to store information and burn bitcoin.(3)A semi-structural covert communication scheme based on blockchain multi-carrier collaboration is designed.Use the multiple fields generated when the blockchain to construct the transaction as the carrier,and use the semi-structural information hiding method to embed the secret information;use the hash algorithm to ensure that the encrypted fields are not special,set the pre-shared key to ensure the security of communication,and at the same time ensure Continuation of communication;use Elliptic Curve Diffie-Hellman Key Exchange Algorithm(ECDH)to quickly identify transactions and implement address updates.The proposed scheme has been tested in the real Bitcoin blockchain network to verify its security,usability and efficiency.