Coupons and discounts are essential in modern marketing to attract new customers and improve sales. Digital marketing has further amplified their impact, making electronic coupons (e-coupons) a key strategy for targeted promotions. However, e-coupons are vulnerable to fraud. Counterfeit coupons, phishing scams, and malware attacks pose risks to both businesses and customers. These threats emphasize the need for secure and privacy-preserving e-coupon systems. Proximity marketing, which uses location-based technologies to engage customers in real-time, has emerged as an effective tool for targeted promotions. Businesses can send personalized offers to customers in proximity, enhancing engagement and conversion rates. This paper presents a privacy-preserving e-coupon application that integrates location-based marketing while maintaining user anonymity. Our approach enables businesses to measure the impact of e-coupon distribution on marketing by providing fine-grained location-based statistics without compromising user privacy. The security and privacy of the protocol for the privacy-preserving e-coupon application are formally verified using ProVerif.

Fake base stations (FBSs) can carry out attacks against mobile devices and user equipment (UE). We tackle the problem of localizing an FBS after its existence has been detected. Karaçay et al. (2021) have presented a localization method based on the values of the Reference Signal Received Power (RSRP), reported in the standardized measurement reports of the 3rd Generation Partnership Project (3GPP) and sent by the UEs. We show that the method they have proposed fails if the FBS uses a directional antenna (instead of an omnidirectional antenna). The localization method by Karaçay et al. is based on half-planes. We propose a new method that localizes FBSs using a directional antenna by first employing a half-plane method and then applying a method based on convex hulls. Our tests for the new method on data derived from Network Simulator 3 (ns-3) show that it significantly outperforms the previous method for a directional FBS antenna.