document: Distributing private data in challenged network environments Developing countries face significant challenges in network access , making even simple network tasks unpleasant . Many standard techniques - caching and predictive prefetching - help somewhat , but provide little or no assistance for personal data that is needed only by a single user . Sulula addresses this problem by leveraging the near-ubiquity of cellular phones able to send and receive simple SMS messages . Rather than visit a kiosk and fetch data on demand - a tiresome process at best - users request a future visit . If capacity exists , the kiosk can schedule secure retrieval of that user 's data , saving time and more efficiently utilizing the kiosk 's limited connectivity . When the user arrives at a provisioned kiosk , she need only obtain the session key on-demand , and thereafter has instant access . In addition , Sulula allows users to schedule data uploads . Experimental results show significant gains for the end user , saving tens of minutes of time for a typical email\/news reading session . We also describe a small , ongoing deployment in-country for proof-of-concept , lessons learned from that experience , and provide a discussion on pricing and marketplace issues that remain to be addressed to make the system viable for developing-world access .
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