6 回答
lorawan节点入网,这里的nonce很重要
MIC消息完整性编码,相关性
For over-the-air-activation, end-devices are not personalized with any kind of network key. Instead, whenever an end-device joins a network, a network session key specific for that end-device is derived to encrypt and verify transmissions at the network level. This way,roaming of end-devices between networks of different providers is facilitated. Using both a network session key and an application session key further allows federated network servers in which application data cannot be read or tampered with by the network provider.
Establishing these two session 1 keys allows for a federated network server infrastructure in which network operators are not able to eavesdrop on application data. In such a setting, the application provider must support the network operator in the process of an end
device actually joining the network and establishing the NwkSKey for the end-device. At the same time the application provider commits to the network operator that it will take the charges for any traffic incurred by the end-device and retains full control over the AppSKey used for protecting its application data.
以上摘自 LoRaWANSpecification1R0 Spec。
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安全与否不能仅仅看加密算法,还需要关注join trim过程,另外现在绝大多数云平台为了安全性的做法每个device都有独立的devkey哪怕你是同一款产品appkey,这种方式牺牲了产线上时间消耗。
另外LoRaWAN也是采用同样的做法,不过用户可以根据实际的安全性考虑选择是否独立烧写key还是自动根据mac等生成key。
参考Spec的说明,
Each device should have a unique set of NwkSKey and AppSKey. Compromising the keys of one device shouldn‘t compromise the security of the communications of other devices. The process to build those keys should be such that the keys cannot be derived in any way from publicly available information (like the node address for example). 这家伙很懒,还没有设置简介