中文摘要：

随着无线射频识别（Radio Frequency Identification,RFID）系统发展,众多安全和隐私的相关应用对隐私保护认证（Privacy-Preserving Authentication,PPA）技术提出了强烈需求.而PPA应用的先决条件是合法读写器和标签之间存在共享密钥.但由于无线信道的开放性,读写器直接向标签写入的密钥会被敌手轻易窃听;此外,RFID标签的计算、存储和通信能力极其有限,导致现有的密钥协商协议不能应用于RFID系统;再者,标签生产商在标签出厂时写入的密钥会带来密钥托管问题并且用户不能自定义密钥.上述原因导致RFID系统中密钥安全生成问题极具挑战性.该文创新性地利用RFID系统中信道不对称性,提出了一种RFID系统密钥无线生成方法WiKey.WiKey是一种轻量级协议可在现有的RFID系统中实现.通过全面的安全性分析,我们展示了WiKey能为PPA协议提供强有力的保护;在WISP标签上的原型实现以及实际测试表明WiKey在现有RFID系统中实现的可行性和高效性.

英文摘要：

As Radio Frequency Identification （RFID） systems have been enormously applied in fields like commerce and logistics, a wide spectrum applications call for Privacy-Preserving Authentication （PPA） in RFID systems, which require a legitimate reader to share secret keys with one or group of tags. With open wireless channels, an adversary can easily obtain keys sent to tags by the reader. Moreover, existing key-agreement approaches cannot be employed in RFIDs as tags are usually resource-constraint. Furthermore, keys implanted by manufacturer cannot be considered as secure due to two-fold reasons： the most trustworthy keys are those generated by users themselves and the key-escrow on the manufacturer incurs key-leaking problem. Hence, it is very challenging to generate shared secret keys among a valid reader and tags wirelessly and securely. In this paper, we propose an innovative wireless key generation scheme, called WiKey, with which a legitimate reader can generate secret keys among itself and tags by effectively utilizing the asymmetry of communication channels of RFID systems. WiKey is a very light-weighted protocol and can be implemented on current RFID systems. Through intensive security analysis, we show that WiKey is an efficient and strong protection for PPAs in RFID systems. Moreover, the implementation on WISP RFID tags and experiment results illustrate the feasibility and efficacy of WiKey.