Video (

Rural areas in developing regions often have poor access to information. Although traditional channels such as radio and TV have broad coverage, they do not provide one-to-one communication, which is necessary for conducting transactions, providing customized training, and medical consultation. Several approaches to rural communication have been attempted in the past, including dial-up telephony, VSAT terminals, long-range wireless, and cellular telephony. Each of these approaches has its pros and cons, but all of them are unreliable or unaffordable in rural contexts. Our approach, instead, is to rely on two nearly-ubiquitous technologies: USB memory keys and SMS.

USB memory keys are an amazing technology. They are cheap, widely available, and have no moving parts. They can carry gigabytes of information and be easily carried from place to place. They can even be mailed in the postal system. These features make them ideal for data communication in developing countries.

Unfortunately, USB keys have their problems as well. Keys can be lost and, if they are not protected, their contents can be read. Keys cannot be conveniently shared amongst multiple users. Moreover, if used to transfer data from one PC to another, the sending PC has no way to learn that a file has been successfully received. For these reasons, USB keys are used to transfer data between PCs in an ad hoc manner, relying on users to track transfers and ensure confidentiality.

In recent work, our team has found a way to overcome these problems. After installation of our free, open-source software on two PCs running Windows XP Pro, simply carrying a key from one to the other from time to time establishes a secure communication link. This link can be used by an otherwise unconnected PC to access the Internet, for example to send and receive email. With our solution, a user at a village far from the Internet can still send and receive email using standard email providers such as Gmail, Yahoo, and Hotmail.

To make our solution secure, the keys carry encrypted data readable only by the intended recipient. This allows a single key to be shared by many users. Moreover, even if a key is lost, no data can be read.

Besides the use of USB keys for communication, a technology we call 'KeyLink,' our solution provides two other robust communication technologies. With SMSLink, a cellphone attached to each of the communicating PCs allows SMS messages to be exchanged between them. Our software allows email to be sent on this connection for short, urgent messages. Users do not need to worry about their email fitting into 140 characters or about lost messages: SMSLink takes care of these details automatically.

In many cases, rural kiosks are often connected to towns and cities over unreliable dialup links. Our TCPLink software allows robust communication over such links. Our software automatically re-establishes connections whenever a dialup connection is restored. Moreover, all data sent over TCPLink can be optionally encrypted, making it even more secure.

Finally, VLink continues to work despite power outages or computer failures by storing all data and program state in a database

To install our VLink, you only need to download a few files and purchase one USB key.

June 10, 2009: VLink Beta for Windows XP Pro released! Click here to download



VLink is free and open-source with no patent, copyright or intellectual property restrictions, under the Apache license.

In a base installation, VLink requires only two Windows XP Pro desktop computers and one USB key to provide email service to an otherwise unconnected desktop. There are NO ongoing operational costs. This is hundreds of times cheaper than other solutions.

VLink is rapidly deployable. You only need to download one file, follow simple installation directions (which will take about 20-30 minutes) and the system is ready for use.

VLink is robust to power outages. Data is stored in a database, so that communication proceeds despite arbitrary failures of network nodes.

VLink has extensive support for system security. It allows users to exchange private email using PKI.

VLink ships with an easy-to-use API and some sample applications.

Who can use VLink?

Vlink can be used by:

  • Non-governmental organizations (NGOs) for communication between headquarters and field offices
  • Hospitals for consultation between district hospitals and headquarters
  • Rural Business Process Outsourcing (BPO) to deliver data for keyboarding and pick up processed forms
  • Community Service Centers (kiosks) to offload bulk data transfer from dialup links to vehicles ('mechanical backhaul')
  • Educational institutions for outreach using audio/video

Some technical details

VLink provides a single software interface for disconnection-tolerant applications, such as email, to access multiple underlying technologies. Files placed in a 'communication directory' on a client or proxy server are opportunistically transmitted on any available link technology and appear in a corresponding directory on the other end. This directory based Application Programmer Interface abstracts complex underlying technologies and simplifies application development. Moreover, VLink provides a new type of link, based on the insertion, transfer, and removal of USB-based memory keys. KeyLink provides high-bandwidth, high-delay communication even in areas that are otherwise completely disconnected.

VLink is designed to provided reliable communication in environments that suffer from poor dial-up quality, lost SMS messages, or intermittent failures on long-range wireless links. Moreover, because all program state is kept in a crash-proof database, end-systems can be arbitrarily powered down with no loss of data. This makes VLink suitable for rural areas with poor quality electrical power.

VLink relies on three underlying technologies:

All three provide communication between a proxy node, which typically has reliable Internet access, and a client node, which typically does not.

VLink implements PKI to allow all data transfer to be encrypted. Details can be found here.

To dig deeper

The VLink software architecture can be found here. VLink grew out of our experiences with the KioskNet system. A video of a talk describing KioskNet delivered at Google in March 2006 and titled Low-Cost Internet Access using mechanical backhaul ( is available on Google video (

The Waterloo Record also did a feature piece ( on KioskNet in Mar 2008. A pdf version of this is here (

We have published several papers on KioskNet, which you can find here (

Contact Us

Prof. S. Keshav


Phone: +1 519 888 4567 x34456

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