Abstract: In available trust based recommendation schemes, users always tend to transact with the entity with the highest trust value, which will result in the fact that the virtual community's resource cannot be fully utilized. The entity with the highest trust value will also delay the response because of its capacity constraint, so that its trust value will be bound to decline. To resolve this problem, we propose a recommendation algorithm which takes the community benefit and the stability of the entities' trust value into account. The community's control center adopts the Lyapunov optimization method to make a decision which can give it the maximum benefit on the premise of satisfying the desired constraint of the interaction requester, meanwhile guaranteeing the stability of the community nodes' trust value. Theoretical analysis and experiments show that our algorithm can stabilize the community nodes' trust value, and that it also can enable the whole community and resource requester to get more benefits.

Key words: virtual community, internet of things, network security, trust recommendation algorithm, Lyapunov optimization