After　analyzing　the　merits　and　shortcomings　of　some　current　authentication　protocols　for　roaming　in　wireless　mesh　networks　(WMNs),　we　propose　a　new　protocol　for　roaming　based　on　multi-signature　and　three-party　key　agreement　in　this　paper　and　prove　the　security　of　the　protocol　through　formal　analysis　based　on　the　strand　space　model.　We　also　show　the　reliability　and　performance　gain　of　the　protocol　using　network　simulation.　©　2010　IEEE.