A Protocol for Preventing Transaction Commitment Without Recipient's Authorization on Blockchain and It's Implementation

In recent years, blockchain is utilized practically as a distributed secure digital ledger of some sorts of transactions. Blockchain is regarded as one of the most important next generation infrastructure technologies of the financial industry, as well as artificial intelligence and big data. In 2020, cryptocurrencies based on blockchain, such as Bitcoin, Ethereum, or XRP, have a value of more than $450 billion in the market capitalization. Furthermore, on blockchains such as Ethereum, transactions can also represent automatic executions of programs, which are called smart contracts. Thus, many institutes in various categories show their positive attitude toward processing financial transactions or non-financial contracts on blockchain. Although many researchers have studied for various types of issues on blockchain, there always exist security and privacy concerns for blockchain. In this paper, we point out a new concern for abusing the publicity of blockchain and also show the possibility of suspicions aroused by the concern. Then we propose a selective mechanism for self-protecting against the approach from crimes or computer viruses on blockchain, whether the disclosure of user's privacy occurs or not. Next, we also propose a concrete implementation of our proposed selective mechanism with two new address types. We aim to incorporate the mechanism in Bitcoin Core, which is the official Bitcoin client software, and using libbitcoin library functions for Bitcoin software development. We show experimental results to estimate overhead costs for processing our proposed address types toward processing the current standard address type in nodes on the peer-to-peer network.