Design of an anonymity-preserving three-factor authenticated key exchange protocol for wireless sensor networks.

•We observed that Farash et al.’s authentication protocol for WSN is susceptible to many security attacks.•The protocol is also unable to preserve user anonymity.•We designed an anonymity preserving authentication scheme for WSN.•We analyze the security of the proposed protocol using AVISPA S/W.•The proposed protocol is secure against active and passive attacks and more efficient than other protocols.