Study On Solutions And Issues Of Reliable Virtual Transaction

Virtual economy develops rapidly and accounts for quite a large proportion in the entire economy. Now it plays an important role in everyday life. Markets of virtual goods and services, especially in the fields of online games, apps and cloud services, are quite active and contribute a lot to the revenue. Usually these transactions are carried out on online platform using virtual currency rather than real one. Due to the high frequency and small-valued size of virtual transactions, it is inconvenient for both sides to use a real currency. Thus virtual currency is widely adopted. Owing to the lack of strong supervision and effective regulation in virtual economy, it is necessary and significant to build a virtual transaction system with security, reliability, transparency and high performance to maintain the market order. Based on the existing research, this paper builds a model of reliable virtual transaction system, proposes a concrete solution using cryptographic technology, defines and analyzes the key properties of system.In this paper, we propose a virtual transaction system composed of four parties: Platform, Provider, Player and Payment. The main interactions include purchasing e-coins, consuming and encash. In order to make the system less rely on the Platfor-m’s trustworthiness and enhance the system’s transparency, the e-coin adopted in this scheme is bound with the price. It also requires the Platform to prove the aggregate value of a batch of cashed e-coins without revealing any individual one’s value. Fur-thermore, we introduce the new participant Payment in our system to detect the possible collusion between Platform and Player.According to the model and issues above, we implement our scheme 4P_VES with the combination of cryptographic primitives such as homomorphic commitment, dynamic accumulator, signature, etc. We make use of commitment to bind the e-coin with the real price. The homomorphism is a good property for generating the proof of the aggregate value of a batch of e-coins. Dynamic accumulator is adopted to maintain the users’virtual accounts, which is efficient to add or delete e-coin to/from a large set. Considering the performance, a variant of 4P_VES is also proposed, which is a tradeoff between security and communication efficiency. Meanwhile, improved ideas are also proposed in our paper, making use of multisignature and merging some primitives. This paper also defines and discusses the properties of e-coin and virtual economy including unforgeability, unreusability, consistency, indistinguishability, authenticity, transparency and collusion-resistance.We also describe the attack models and prove the security of our scheme based on the cryptographic assumptions. This paper also evaluates the performance of 4P_VES and compares it with different schemes to illustrate the practicability and advantages of our solution. The theoretical proof and experimental simulation show that our sys-tem is a reliable and practical one which enhances the transparency and reduces the dependency on Platform’s honesty.