Federated Identity Management schemes (FIdMs) are of great help for traditional systems as they improve user authentication and privacy. In this paper, we claim that traditional FIdMs are mostly cumbersome and then ill-suited for IoT. As a solution to this problem, we came up with Federated Lightweight Authentication of Things (FLAT), namely a federated identity authentication protocol exclusively tailored to IoT. FLAT replaces weighty protocols and public-key cryptographic primitives used in traditional FIdMs by lighter ones, like symmetric cryptographic primitives and Implicit Certificates. Our results show that FLAT can reduce the data exchange overhead by around 31% when compared to a baseline solution. Also, the FLAT Client, the role played by an IoT device in the protocol, is more efficient than the baseline Client in terms of data exchange, storage, memory, and computation time. Our results indicate that FLAT runs efficiently, even on top of resource-constrained devices like Arduino.

联合身份管理方案（FIdM）对传统系统有很大帮助，因为它们可以改善用户身份验证和隐私。在本文中，我们认为传统的FIdM繁琐，因此不适合物联网。为了解决这个问题，我们提出了物联网联合轻量认证（FLAT），即专为物联网量身定制的联合身份认证协议。FLAT用较轻的协议代替了传统FIdM中使用的重协议和公钥密码原语，例如对称密码原语和隐式证书。我们的结果表明，与基准解决方案相比，FLAT可以减少大约31％的数据交换开销。此外，FLAT客户端（物联网设备在协议中扮演的角色）在数据交换方面比基准客户端更有效，存储，内存和计算时间。我们的结果表明，即使在像Arduino这样的资源受限的设备之上，FLAT仍可以高效运行。