AbstractThis paper investigates the leakage rate based untrustworthy relay selection strategies, which are based on the untrustworthy relay terminals operate in half‐duplex, full‐duplex, and hybrid modes. The investigation considers a dual‐hop one/two‐way half/full‐duplex wireless relaying network in the system model. The investigation also considers that a finite number of friendly jammers affect the untrustworthy relay terminals. According to analytical, asymptotic, and Monte Carlo simulation results, the LR‐based untrustworthy relay selection strategies achieve cooperative diversity order in high‐signal‐to‐noise ratio. However, friendly jammers and loop interference severely affect the system performance and degrade the achievable diversity order from M to 0 and also cause system coding gain losses. In addition, friendly jammers and loop interference also degrade the system achievable rate performance and cause saturation in high SNRs.