Existing proactive secret sharings (PSSs) are all based on the synchronous time model and reliable links assumptions

which are impractical in distributed environments

such as Internet.This paper proposes a practical PSS for asynchronous networks with unreliable links.The asynchronous PSS is obtained by introducing a concept of time phase

which is defined not only in terms of protocol events

but also in timings of all participants.Based on this concept

the states and their transitions of asynchronous PSS can be characterized.And

the reliable communications between participants are yielded by the development of a reliable message transmit protocol.Analyses show that our method is efficient

and has a low overhead in terms of communication and computation.