With　dramatic　advances　in　networking,　wireless　mesh　networks　are　widely　used　for　emergency　services　to　improve　the　efficiency　of　public　safety　communication　to　prevent　or　respond　to　incidents　that　harm　or　endanger　persons　or　property.　In　this　paper,　we　propose　a　privacy　enhanced　scheme　of　key　exchange　using　directed　signature　for　public　safety　communication　in　wireless　mesh　networks.　In　the　result,　only　both　participants　can　gain　the　shared　secret　key,　however,　any　party　else　can　not　understand　the　key　exchange　process　clearly.　We　analyze　the　properties　of　security　and　efficiency　of　the　scheme　in　comparison　to　a　practical　scheme　of　key　exchange　with　asymmetric　encryption.　The　results　of　experiment　show　that　the　scheme　can　provide　resistance　to　the　unknown　key-share　attacks,　privacy　protection　for　sensitive　information　included　in　signature　and　better　efficiency　in　terms　of　computational　cost.