Supporting BlockchainBased Cryptocurrency Mobile Payment With Smart Devices The smart device owning rate such as smart phone and smart watch is higher than ever before and mobile payment has become one of the major payment methods in many different areas. At the same time, blockchainbased cryptocurrency is becoming a nonnegligible type of currency and the total value of all types of cryptocurrency has reached USD 200 billion. Therefore, it is a natural demand to support cryptocurrency payment on mobile devices. Considering the poor infrastructure and low penetration of financial service in developing countries, this combination is especially attractive. The high storage cost and payment processing latency are the two main obstacles for mobile payment using cryptocurrency. We propose two different schemes for cryptocurrency mobile payment, one involves a centralized bank and the other one does not require any centralized party. We also provide a solution for the bank to meet KYC (know your customer)AML (antimoney laundering) compliance requirements when it is involved in cryptocurrency mobile payment processing.

What is Stablecoin?: A Survey on Price Stabilization Mechanisms for Decentralized Payment Systems Since the first theoretical concept of blockchains was proposed, over 100 digital currencies have been issued by online platformers as cryptocurrencies and traded by online consumers mainly in emerging countries. From the perspective of online payment systems, several studies have regarded blockchains as decentralized payment systems (DPSs), enabling international payment with lower cost and higher traceability with sophisticated peertopeer protocols in contrast to other centralized systems. Despite the advantages, DPSs are not chosen by the owners of online shops due to the high volatility of cryptocurrency prices. Stablecoins are cryptocurrencies with price stabilization mechanisms to match the price of another currency with lower volatility. Our motivation is to gather various price stabilization mechanisms for the purpose of comparing them from the perspective of implementation and enterprise usage. After dividing the methods into four collateral types (fiat, crypto, commodity, and noncollateralized) and two layers (protocol and application), we show that noncollateralized stablecoin on the application layer is the simplest approach for implementation. Moreover, we discuss their connection with traditional economic studies on Hayek money, Seigniorage Share, and Tobin tax. Some current stablecoin projects are also discussed and compared. This is the first survey of stablecoins to the best of our knowledge.