抗位置隐私泄露的物联网频谱共享激励机制

A Spectrum Sharing Incentive Scheme Against Location Privacy Leakage in IoT Networks

海量的物联网设备涌入,在加剧频谱资源紧缺的同时,仍存在着大量授权用户的频谱资源未被充分利用的矛盾.对授权用户的空闲频谱实施共享是解决这一矛盾的关键所在.然而,出于自私性和顾虑位置隐私泄露,一些授权用户不愿共享其空闲频谱,将会严重制约频谱共享在物联网中的有效实施.鉴于此,采用Geohash编码前缀和二进制编码后缀相结合的k匿名区域位置编码方式,设计编码优化的Casper模型(GB-Casper).该模型以授权用户所需的最小匿名区域面积A min控制Geohash编码长度,利用二进制编码进行k匿名区域的细粒度划分,通过字符串比较运算判断生成的k匿名区域中是否包含k-1个用户,以此减少二进制编码位数来逐渐扩大扫描区域,得到满足位置隐私保护的k匿名区域代替授权用户真实位置.引入频谱贡献度,连同位置隐私保护水平量化到博弈模型中,形成抗位置隐私泄露的物联网频谱共享激励机制.仿真结果表明,提出的方案可以快速构建k匿名区域,在防止位置隐私泄露的条件下,能有效激励授权用户积极参与频谱共享.

The influx of massive IoT devices can aggravate the shortage of spectrum resources,while the contradiction that a large number of licensed spectrum resources are underused.The key to resolve this issue is to adopt spectrum sharing.However,some licensed users(LUs)are reluctant to share their idle spectrum due to selfishness and concerning about location privacy leakage,which will seriously restrict the effective implementation of spectrum sharing in IoT Networks.In view of this,a Casper model(GB-Casper)for coding optimization is designed by combining the Geohash encoding prefix and binary encoding suffix with k anonymous region location encoding method.This model employs the minimum area of anonymous region(A min)required by LUs to control the length of Geohash code,and utilizes the binary code to divide k anonymous region in a fine-grained way.Through the string comparison operation,it can determine whether the generated k anonymous region contains k-1 users,so as to reduce the binary number of encoding bits to gradually expand the scan region,and thus achieving the k anonymous region satisfying the protection of location privacy to replace the authorized users real location.The spectrum contribution degree is introduced,which is quantified into the game model together with the level of location privacy protection to form an incentive scheme for IoT spectrum sharing against location privacy leakage.Simulation results show that the proposed scheme can quickly construct k anonymous region and effectively motivate LUs to actively participate in spectrum sharing while preventing location privacy leakage.