Towards a Cryptographic Model for Wireless Communication: Extended Version
摘要
In cryptography, the Man-in-the-Middle Model (MitMM) is a widely used model for formally representing attackers in multi-party communication scenarios. It assumes that an attacker has unrestricted control over the communication, including the ability to intercept, block, and modify messages at her discretion. However, we show that the MitMM is too strong for accurately capturing the peculiarities of wireless communication. Consequently, the MitMM cannot accommodate security mechanisms that leverage unique wireless properties, such as friendly jamming or Distance Bounding (DB) protocols. Moreover, the absence of a specialized model hinders the design and formal analysis of new wireless security schemes. To address these limitations, we introduce a novel formal Wireless Communication Model (WCM) tailored to the wireless domain. Building on the MitMM, our model incorporates three key elements missing in the traditional MitMM: communication channels, signals, and locality. These aspects allow for a more realistic representation of wireless communication. To illustrate the model’s utility, we provide a concrete example of representing QPSK modulation within our model. With the WCM as a basis, we define a Wireless Attacker Model, which formally captures the constraints faced by attackers in wireless environments. Using our model, we formalize the concept of friendly jamming and propose a new security notion, \(\textsf{IND}\text {-}\textsf{CSA}\text {-}{n}\) (Indistinguishability under Chosen Signal Attack). We further demonstrate the utility of our model by providing a formal security proof for DB protocols.