Smartcard-based protocols represent an increasingly large share of the wireless authentication market, from contactless payments to remote car unlocking. Unfortunately, relay attacks pose a significant threat to these wireless solutions. However, this risk can be mitigated through the use of distance-bounding protocols. In this paper, we discuss the core challenges for distance-bounding, in terms of both theoretical and practical considerations. We focus on their security, but we also explore the difficulties encountered in their design and implementation. Moreover, we present our vision of the future of these protocols and of the possible paths towards their secure deployment.