Physical Layer Secret Key Generation in Static Environments
Physical Layer Secret Key Generation in Static Environments
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DOI：
10.1109/tifs.2020.2974621
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发表时间：
2020-01-01
影响因子：
6.8
通讯作者：
Mahdavifar, Hessam
中科院分区：
文献类型：
--
作者：
Aldaghri, Nasser;Mahdavifar, Hessam
称为Alice和Bob的两个合法方希望在称为Eve的窃听者在场的情况下从无线信道生成秘密密钥，以便使用这样的密钥进行加密和解密。通常，密钥速率高度依赖于信道的相干时间。特别是，在静态环境中生成密钥的直接方法导致超低速率。为了解决这个问题，我们引入了一种称为诱导随机性的低复杂度方法。在该方法中，Alice和Bob独立地生成与无线信道系数的唯一性一起使用的局部随机性，以实现高速率密钥生成。在这项工作中，考虑了两种情况：第一，当Alice和Bob共享直接通信信道时；第二，当Alice和Bob没有直接链路并且通过不可信的中继进行通信时。在交换诱导随机性之后，Alice和Bob进行后处理，以生成用于密钥生成的高度相关的样本。然后将这样的样本转换成比特，减轻由Alice和Bob生成的序列之间的差异，然后对得到的序列进行散列，以补偿向窃听者泄露的信息并允许对生成的密钥比特序列进行一致性检查。我们利用语义安全度量和信息论不等式，根据可数值计算的互信息度量，给出了窃听攻击成功概率的上界。在给定某些合理的系统参数的情况下，在第一种和第二种情况下，这个界限分别被数值评估为2(-31)和2(-10.57)。
Two legitimate parties, referred to as Alice and Bob, wish to generate secret keys from the wireless channel in the presence of an eavesdropper, referred to as Eve, in order to use such keys for encryption and decryption. In general, the secret key rate highly depends on the coherence time of the channel. In particular, a straightforward method of generating secret keys in static environments results in ultra-low rates. In order to resolve this problem, we introduce a low-complexity method called induced randomness. In this method, Alice and Bob independently generate local randomness to be used together with the uniqueness of the wireless channel coefficients in order to enable high-rate secret key generation. In this work, two scenarios are considered: first, when Alice and Bob share a direct communication channel, and second, when Alice and Bob do not have a direct link and communicate through an untrusted relay. After exchanging the induced randomness, post-processing is done by Alice and Bob to generate highly-correlated samples that are used for the key generation. Such samples are then converted into bits, disparities between the sequences generated by Alice and Bob are mitigated, and the resulting sequences are then hashed to compensate for the information leakage to the eavesdropper and to allow consistency checking of the generated key bit sequences. We utilize semantic security measures and information-theoretic inequalities to upper bound the probability of successful eavesdropping attack in terms of the mutual information measures that can be numerically computed. Given certain reasonable system parameters this bound is numerically evaluated to be 2(-31) and 2(-10.57) in the first and the second scenario, respectively.