Provably Secure Covert Communication on Blockchain

Abstract

Blockchain is a public open ledger that provides data integrity in a distributed manner. It is the underlying technology of cryptocurrencies and an increasing number of related applications, such as smart contracts. The open nature of blockchain together with strong integrity guarantees on the stored data makes it a compelling platform for covert communication. In this paper, we suggest a method of securely embedding covert messages into a blockchain. We formulate a simplified ideal blockchain model based on existing implementations and devise a protocol that enables two parties to covertly communicate through the blockchain following that model. We also formulate a rigorous definition for the security and covertness of such a protocol based on computational indistinguishability. Finally, we show that our method satisfies this definition in the random oracle model for the underlying cryptographic hash function.

Blockchain Technology Implementation in Logistics

“…There are three main advantages of blockchain compared to other cover mediums: (1) it is anonymous and free to join, meaning that the communication parties have free access; (2) submitted data cannot be altered and, in particular, the integrity guarantees are not provided by any centralized party, but rather the consensus of the entire network; and (3) published data cannot be removed, meaning that no authority can apply censorship to already published data. Since the blockchain is immutable, alteration of the covert messages is virtually impossible, and the embedding of covert information is free to be fragile [8].…”

“…The changes made by the various parties are collected and stored in the database at regular intervals as bundled packets called 'blocks' [7].There are three main advantages of blockchain compared to other cover mediums: (1) it is anonymous and free to join, meaning that the communication parties have free access; (2) submitted data cannot be altered and, in particular, the integrity guarantees are not provided by any centralized party, but rather the consensus of the entire network; and (3) published data cannot be removed, meaning that no authority can apply censorship to already published data. Since the blockchain is immutable, alteration of the covert messages is virtually impossible, and the embedding of covert information is free to be fragile [8].For better understanding of this paper, blockchain is defined as follows: "blockchain is a distributed database, which is shared among and agreed upon a peer-to-peer network. It consists of a linked sequence of blocks, holding time stamped transactions that are secured by public-key cryptography and verified by the network community.…”

Whispers on Ethereum: Blockchain-based Covert Data Embedding Schemes

“…Juha [16] proposed a blockchain-based covert channel (BLOCCE) scheme in which a transaction can carry one bit in the field of payments. This is the first formal proved covert data embedding scheme in blockchain systems.…”

“…In order to solve this problem, several works built covert channels in the blockchain systems recently. For examples, a provably secure covert communication scheme was proposed to use the destination address to embed secret data [16]. Later, Gao et al [11] proposed a signature-identifiable algorithm to enhance the covertness of the solution.…”

Survey on Privacy Preserving Technique of Blockchain Algorithm and its Data Structure

“…The drastic rise in blockchain technology has created many fresh possibilities for implementation, including apps for healthcare [1]. The terms ' blockchain' and' distributed ledger technology'(' DLT') are frequently used interchangeably Also suggest in [4] a method of securely embedding covert Blockchain messages. We formulate a simplified ideal blockchain model based on existing implementations and develop a protocol that allows two parties to communicate secretly following that model through the blockchain.…”