The One Laptop per Child (OLPC) project attempts to utilize practical technologies to put computational tools in the hands of the world’s poorest children. The mission of the One Laptop Per Child project is,
To create educational opportunities for the world’s poorest children by ensuring each child has a rugged, low-cost, low-power, connected laptop with content and software designed for collaborative, joyful, self-empowered learning. As a non-profit, we focus on maximizing our positive impact on children’s lives. With access to these tools, children become connected to each other, to the world and to a brighter future. (“One Laptop per Child (OLPC),” 2010)
The project has found, not surprisingly, that Internet access is a challenge in the poorest regions of the world. Telecommunications infrastructure in remote, poverty stricken areas is inadequate for digital communications and often non-existent. To further the mission of providing connectivity, even in areas with limited connectivity, the devices distributed to children by One Laptop per Child include mesh network capabilities based on the IEEE Internet Engineering Task Force’s 802.11s draft standard. (“Mesh Network Details,” 2010) The mesh network utilized in the One Laptop per Child device represents a peer-to-peer (P2P) networking technology that enables Internet connectivity despite large separation from wireless access points or other traditional Internet connectivity technologies. An analysis of the OLPC implementation illustrates several key design considerations for any peer-to-peer technology, including topology and security.
The implementation of a self-organizing, mesh network was a design priority for OLPC. As Buchele states in her case study of the OLPC device, “Interconnectivity was a design priority, although it was recognized that children in developing countries would have limited access to the usual wired or wireless connectivity infrastructure (routers, repeaters, Ethernet, modems).” (Buchele, 2009) The connection to the Internet is provided by a machine at the school, referred to as the School Server in OLPC documentation. Mary Lou Jepsen, Chief Technology Officer for OLPC, best summarizes the success of the mesh network as a P2P conduit for Internet connectivity in a 2007 interview,
If one laptop in a village is connected to the Internet, they all are. Yes, it might be just a trickle, a low-bandwidth con- nection from the Internet to the laptop, but between the laptops is a high-bandwidth connection through the mesh network. (Stanik, 2007)
The laptop utilizes a System on a Chip (SOC) architecture that includes as 802.11b/g (WiFi) wireless interface. To facilitate the mesh networking, “the laptops are able to route traffic as a mesh point even if the main CPU is off, an added power saving feature.” (Buchele, 2009) Using the mesh network, with it’s self-organizing and always-on routing, children in remote areas are able to connect to the Internet by the peer-to-peer nature of the mesh.
Circa 2008, OLPC had placed approximately 5 million laptops with P2P, self-organizing, mesh network capabilities into the hands of the world’s children. (Krstic & Garfinkel, 2007) Security was an important factor in the design of the laptop, both due to child protection issues and concerns about compromised machines being used as attack platforms. OLPC’s designers identify five critical threat vectors, “software attacks on the laptop hardware, attacks on operating system integrity, user data loss, attacks on user control of the laptop (and laptop ownership), and attacks on user privacy.” (Krstic & Garfinkel, 2007) Within the scope of P2P network security, theft and privacy were the main concerns. A cryptographic public key system is fully integrated into the laptops to provide protections against these threats. Figure 1 illustrates the main points regarding the design of the public key system and the initial distribution of keys.
Figure 1 OLPC Public Key Protection System (Krstic & Garfinkel, 2007)
The anti-theft system enables laptops to be deactivated and blocked from participating in the mesh network if reported stolen. Students that desire additional privacy are able to utilize their cryptographic keys to establish a virtual private network connection with the School Server. However, there are no content filtering features to protect children from the threat of objectionable material. OLPC has chosen not to address this threat, “Customers who desire filtering of material of sexual, political or religious nature will almost certainly implement these filtering policies at the schools using special-purpose software or at the national level.” (Krstic & Garfinkel, 2007)
Peer-to-peer networks provide novel features compared to traditional networks. The One Laptop per Child project has leveraged P2P in the design and implementation of a mesh network that provides Internet connectivity to children in the poorest, most remote places of the Earth. By utilizing the P2P model, OLPC hopes to connect the world’s neediest children to the vast educational resources available on the Internet.
Buchele, S. F. (2009). Using OLPC laptop technology as a computer science case study teaching tool. J. Comput. Small Coll., 24(4), 130-136.
Krstic, I., & Garfinkel, S. L. (2007). Bitfrost: the one laptop per child security model. Paper presented at the Proceedings of the 3rd symposium on Usable privacy and security.
Mesh Network Details. (2010). Retrieved 2/13/2010, 2010, from http://wiki.laptop.org/go/Mesh_Network_Details
One Laptop per Child (OLPC). (2010). Retrieved 2/13/2010, 2010, from http://laptop.org/en/vision/index.shtml
Stanik, J. (2007). A Conversation with Mary Lou Jepsen. Queue, 5(7), 9-15.