Serious price discrimination emerges with the development of big data and mobile networks, which harms the interests of consumers. To solve this problem, we propose a blockchain-based price consensus protocol to solve the malicious price discrimination faced by consumers. We give a mathematical definition of price discrimination, which requires the system to satisfy consistency and timeliness. The distributed blockchain can make the different pricing of merchants transparent to consumers, thus satisfying the consistency. The aging window mechanism of our protocol ensures that there is no disagreement between any node on the consensus on price or price discrimination within a fixed period, which meets the timeliness. Moreover, we evaluate its performance through a prototype implementation and experiments with up to 100 user nodes. Experimental results show that our protocol achieves all the expected goals like price transparency, consistency, and timeliness, and it additionally guarantees the consensus of the optimal price with a high probability.

In recent years, Software-Defined Networks (SDNs) have become a promising technology to improve network utilization. However, limited flow table size and long deployment delays may result in low network performance in large-scale networks and a poor user experience. While a typical solution to this issue is routing aggregation (i.e., wildcard routing), the aggregation feasibility problem and reduced network performance may be encountered. To address this dilemma, we first design a novel wildcard routing scheme, called the Tag-based Rule Placement Scheme (TRPS). We then formulate a Hybrid Routing by Joint optimization of Per-flow routing and Tag-based routing (HR-JPT) problem, and prove its NP-hardness. An algorithm with a bounded approximation factor is designed for this problem, and the proposed methods are implemented on a Mininet platform. Extensive simulation results show that our methods are efficient for wildcard/hybrid routing. For example, our proposed tag-based wildcard rule placement scheme can reduce the number of required rules by about 65% on average compared with previous wildcard routing methods. Our proposed hybrid routing algorithm can increase network throughput by about 43% compared with existing hybrid routing solutions.