Can we make a denial-of-service attacker pay more than the server and honest clients? Consider a model where a server sees a stream of jobs sent by either honest clients or an adversary. The server sets a price for servicing each job with the aid of an estimator, which provides approximate statistical information about the distribution of previously occurring good jobs. We describe and analyze pricing algorithms for the server under different models of synchrony, with total cost parameterized by the accuracy of the estimator. Given a reasonably accurate estimator, the algorithm's cost provably grows more slowly than the attacker's cost, as the attacker's cost grows large. Additionally, we prove a lower bound, showing that our pricing algorithm yields asymptotically tight results when the estimator is accurate within constant factors.

翻译：我们能否让拒绝服务攻击者比服务器和诚实客户端付出更高代价？考虑一个模型，其中服务器接收由诚实客户端或攻击者发送的任务流。服务器借助估计器为每个任务设定服务价格，该估计器提供先前发生的良性任务分布的近似统计信息。我们在不同同步模型下描述并分析了服务器的定价算法，其总成本由估计器的准确性参数化。给定一个合理准确的估计器，当攻击者成本增长时，该算法的成本可证明比攻击者成本增长更慢。此外，我们证明了一个下界，表明当估计器在常数因子范围内准确时，我们的定价算法能产生渐近紧确的结果。