RPL路由协议中基于投票法的黑洞攻击检测算法

物联网容易遭受多类拒绝服务攻击,其中黑洞攻击是最严重的攻击之一.为此,提出基于投票法的黑洞攻击检测算法(Voting Method-based Blackhole Attack Detection,VMBAD).通过VMBAD算法检测RPL协议上的黑洞攻击.先通过过滤器构建嫌疑节点,再验证嫌疑节点的行为,各节点作出自己的决策意见,并传输到边界路由(Bor-der Router,BR).接收后,BR利用投票机制融合各节点的决策意见,进行最终的决策,进而判断节点是否为黑洞攻击节点.一旦认定为黑洞攻击,就将黑洞攻击节点与网络隔离,使其不参与RPL路由.仿真结果表明,VMBAD算法能够有效地检测黑洞攻击节点,并且通过排除攻击节点,提高了数据包传递率.     

Traffic channeling under uncertain conversion rates on e-commerce platforms

Traffic is the lifeblood of every e-commerce platform. The question of how to channel traffic to merchants operating on a platform lies at the heart of platform management. We consider a platform on which two independent merchants sell their products. Merchants compete on inventory in the sense that some of the unmet demand at one merchant will spill over to the other. The platform channels traffic based on products' conversion rates to maximize the total sale on the platform. We show that traffic channeling plays three roles. First, it allows more efficient allocation of traffic; that is, the merchant with a high conversion rate is given a higher priority in receiving traffic. Second, it allows the platform to control demand spillover between the merchants to maximize total sales. The platform either facilitates or prevents demand spillover, depending on product substitutability. Third, traffic channeling intensifies competition between the merchants and hence increases the total inventory. More efficient allocation of traffic and the increase in inventory increase sales inequality between the merchants. In contrast, demand spillover decreases sales inequality. While the platform always benefits from traffic channeling, the merchants do not benefit when their products are moderately substitutable. Interestingly, when the two products are owned and sold by the same merchant, the opposite happens–traffic channeling always benefits the merchant but may hurt the platform. Our study provides a basis for informed discussions on how platforms should channel traffic in response to conversion rates, and how traffic channeling affects the welfare of merchants and platforms.