Systems and techniques for key management in mobile ad hoc networks are described. Pseudonyms are defined for group members of mobile ad hoc networks such that a pseudonym in a message can be deterministically identified with the sending device only by the sending device and the message recipient. Key management for a group is performed by a group manager, and key management may include key renewal and revocation. Key renewal is performed by a group manager, with the group manager using a set of couple pseudonyms, including a couple pseudonym between the manger and each group member. Key renewal employs a renewal key used to encrypt the updated group key, and the group manager updates the group key be transmitting a message to each group member in proximity, with the message being identified using the couple pseudonym of the manager and the group member.