Pervasive Social Networking (PSN) supports online and instant social activities with the support of heterogeneous networks. Since reciprocal activities among both familiar/unfamiliar strangers and acquaintances are quite common in PSN, it is essential to offer trust information to PSN users. Past work normally evaluates trust based on a centralized party, which is not feasible due to the dynamic changes of PSN topology and its specific characteristics. The literature still lacks a decentralized trust evaluation scheme in PSN. In this article, we propose a novel blockchain-based decentralized system for trust evaluation in PSN, called Social-Chain. Considering mobile devices normally lack computing resources to process cryptographic puzzle calculation, we design a lightweight consensus mechanism based on Proof-of-Trust (PoT), which remarkably improves system effectivity compared with other blockchain systems. Serious security analysis and experimental results further illustrate the security and efficiency of Social-Chain for being feasibly applied into PSN.

中文翻译：

---

社会链

Pervasive Social Networking (PSN) 在异构网络的支持下支持在线和即时社交活动。由于熟悉/不熟悉的陌生人和熟人之间的互惠活动在 PSN 中很常见，因此向 PSN 用户提供信任信息至关重要。过去的工作通常基于中心化方来评估信任，由于 PSN 拓扑的动态变化及其特定特性，这是不可行的。文献中仍然缺乏 PSN 中的分散信任评估方案。在本文中，我们提出了一种新颖的基于区块链的去中心化系统，用于 PSN 中的信任评估，称为 Social-Chain。考虑到移动设备通常缺乏计算资源来处理密码谜题计算，我们设计了一种基于信任证明（PoT）的轻量级共识机制，与其他区块链系统相比，显着提高了系统效率。认真的安全分析和实验结果进一步说明了 Social-Chain 应用于 PSN 的安全性和有效性。