It is our great privilege to present before you Volume 20, Issue 1 of the “Scalable Computing: Practice and Experience”. We had received 41 paper submissions from Belgium, Malaysia, Indonesia, Bangladesh, Yemen and India, and selected 12 papers for publication. The acceptance rate of this issue is 29 percent. The aim of this special issue is to give the solutions of opportunistic networks and security challenges as well as to collect other research problems in opportunistic networks for further research. This special issue gives the new dimensions for opportunistic networks in the perspective of research.