Abstract: A group-key distribution protocol is designed which has the capability of self-recovery and coalition-attack-resisting,particularly suitable for highly lossy transmission environment such as wireless sensor networks.The basic method applies Langrange interpolation techniques in timedomain to implement a secrecy fragmentation-reconstruction scheme.This paper precisely specifies the desired security properties,proves the constructed scheme to satisfy all desired properties,analyzes the requirements on computation,storage and bandwidth resources,and proposes two improvements with respect to bandwidth and storage optimization.This paper also discusses the parameter selection problem.