针对基于位置的服务(LBS)中的K-匿名机制以固定的最小匿名度为服务质量(QoS)指标,不能在计算资源允许的条件下为用户提供更高匿名度的问题,提出定义新的QoS指标——匿名结果集势指标R*,用于度量和约束匿名服务和LBS为用户的每次查询所平均消耗的计算资源,在此约束下选择可接受的匿名度.从理论上分析匿名结果集势与匿名度的估算函数关系,据此构造相应的匿名度调节算法.模拟实验的结果与上述理论函数关系吻合很好,证明本文的匿名度调节算法能够将匿名结果集势约束在给定值附近,实现了定义的QoS指标.
A limitation in current design of K-anonymity services for location based services(LBS) is that they only provide a given minimum level of anonymity as QoS guarantee and can't improve the anonymity level for users when service resources are capable.The anonymous query result size was proposed as a new QoS target in order to measure and constrain resource consumption on the K-anonymity service and LBS per user query.Then appropriate anonymity level can be selected under such constraint.Theoretical analysis was performed to find mathematical relation between anonymous query result size and anonymity level,leading to the construction of anonymity level adaptation algorithm.The simulation results accorded well with the theoretical relation.The anonymity level adaptation algorithm can control anonymous query result size to stay around the specified QoS target.