Smart devices have accentuated the importance of geolocation information. Geolocation identification using smart devices has paved the path for incentive-based location-based services (LBS). A location proof is a digital certificate of the geographical location of a user, which can be used to access various LBS. However, a user full control over a device allows the tampering of location proof. Initially, to resist false proofs, two-party trusted centralized location proof systems (LPS) were introduced to aid the users in generating secure location proofs mutually. However, two-party protocols suffered from the collusion attacks by the participants of the protocol. Consequently, many witness-oriented LPS have emerged to mitigate collusion attacks in two-party protocols. However, witness-oriented LPS presented the possibility of three-way collusion attacks (involving the user, location authority, and the witness). The three-way collusion attacks are inevitable in all existing witness-oriented schemes. To mitigate the inability to resist three-way collusion of existing schemes, in this paper, we introduce a decentralized consensus protocol called as MobChain, where the selection of a witness and location authority is achieved through a distributed consensus of nodes in an underlying P2P network of a private blockchain. The persistent provenance data over the blockchain provides strong security guarantees, as a result, the forging and manipulation become impractical. MobChain provides secure location provenance architecture, relying on decentralized decision making for the selection of participants of the protocol to resist three-way collusion problem. Our prototype implementation and comparison with the state-of-the-art solutions show that MobChain is computationally efficient, highly available while improving the security of LPS.

中文翻译：

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MobChain：使用分布式共识的面向证人位置证明系统中的三向共谋抵抗

智能设备凸显了地理定位信息的重要性。使用智能设备的地理定位识别为基于激励的基于位置的服务 (LBS) 铺平了道路。位置证明是用户所在地理位置的数字证书，可用于访问各种LBS。然而，用户对设备的完全控制允许篡改位置证明。最初，为了抵制虚假证明，引入了两方可信集中位置证明系统（LPS）来帮助用户相互生成安全的位置证明。然而，两方协议遭受了协议参与者的串通攻击。因此，出现了许多面向见证的 LPS 来减轻两方协议中的串通攻击。然而，面向见证的 LPS 提出了三向共谋攻击的可能性（涉及用户、位置权限和见证）。在所有现有的面向见证的方案中，三向共谋攻击是不可避免的。为了缓解现有方案无法抵抗三向共谋的问题，在本文中，我们引入了一种称为 MobChain 的去中心化共识协议，其中通过底层 P2P 网络中节点的分布式共识来实现见证人和位置权限的选择一个私有区块链。区块链上持久的来源数据提供了强大的安全保障，因此伪造和操纵变得不切实际。MobChain 提供安全的位置来源架构，依靠分散决策来选择协议的参与者，以抵抗三路合谋问题。我们的原型实现以及与最先进解决方案的比较表明，MobChain 在提高 LPS 安全性的同时具有计算效率、高可用性。