A new distributed mutual exclusion algorithm, using a token and based upon an original rooted tree structure is presented. The rooted tree introduced, named "open-cube", has noteworthy stability and locality properties, allowing the proposed algorithm to achieve good performances and high tolerance to node failures : the worst case message complexity per request is, in the absence of node failures, log2N+1 where N is the number of nodes, whereas 0(log2N) extra messages in the average are necessary to tolerate each node failure. This algorithm is a particular instance of a general scheme for token and tree-based distributed mutual exclusion algorithms, previously presented in part by the authors, consequently, its safety and liveness properties are inherited from the general one, however, the present paper is self-contained.