Systems-compatible Incentives

Originally, the Internet was a technological playground, a collaborative endeavor among researchers who shared the common goal of achieving communication. Self-interest used not to be a concern, but the motivations of the Internet's participants have broadened. Today, the Internet consists of millions of commercial entities and nearly 2 billion users, who often have conflicting goals. For example, while Facebook gives users the illusion of access control, users do not have the ability to control how the personal data they upload is shared or sold by Facebook. Even in BitTorrent, where all users seemingly have the same motivation of downloading a file as quickly as possible, users can subvert the protocol to download more quickly without giving their fair share. These examples demonstrate that protocols that are merely technologically proficient are not enough. Successful networked systems must account for potentially competing interests. In this dissertation, I demonstrate how to build systems that give users incentives to follow the systems' protocols. To achieve incentive-compatible systems, I apply mechanisms from game theory and auction theory to protocol design. This approach has been considered in prior literature, but unfortunately has resulted in few real, deployed systems with incentives to cooperate. I identify the primary challenge in applying mechanism design and game theory to large-scale systems: the goals and assumptions of economic mechanisms often do not match those of networked systems. For example, while auction theory may assume a centralized clearing house, there is no analog in a decentralized system seeking to avoid single points of failure or centralized policies. Similarly, game theory often assumes that each player is able to observe everyone else's actions, or at the very least know how many other players there are, but maintaining perfect system-wide information is impossible in most systems. In other words, not all incentive mechanisms are systems-compatible. The main contribution of this dissertation is the design, implementation, and evaluation of various systems-compatible incentive mechanisms and their application to a wide range of deployable systems. These systems include BitTorrent, which is used to distribute a large file to a large number of downloaders, PeerWise, which leverages user cooperation to achieve lower latencies in Internet routing, and Hoodnets, a new system I present that allows users to share their cellular data access to obtain greater bandwidth on their mobile devices. Each of these systems represents a different point in the design space of systems-compatible incentives. Taken together, along with their implementations and evaluations, these systems demonstrate that systems-compatibility is crucial in achieving practical incentives in real systems. I present design principles outlining how to achieve systems-compatible incentives, which may serve an even broader range of systems than considered herein. I conclude this dissertation with what I consider to be the most important open problems in aligning the competing interests of the Internet's participants

BitTorrent is an Auction: Analyzing and Improving BitTorrent’s Incentives, in:

ABSTRACT Incentives play a crucial role in BitTorrent, motivating users to upload to others to achieve fast download times for all peers. Though long believed to be robust to strategic manipulation, recent work has empirically shown that BitTorrent does not provide its users incentive to follow the protocol. We propose an auction-based model to study and improve upon BitTorrent's incentives. The insight behind our model is that BitTorrent uses, not tit-for-tat as widely believed, but an auction to decide which peers to serve. Our model not only captures known, performance-improving strategies, it shapes our thinking toward new, effective strategies. For example, our analysis demonstrates, counter-intuitively, that BitTorrent peers have incentive to intelligently under-report what pieces of the file they have to their neighbors. We implement and evaluate a modification to BitTorrent in which peers reward one another with proportional shares of bandwidth. Within our game-theoretic model, we prove that a proportional-share client is strategy-proof. With experiments on PlanetLab, a local cluster, and live downloads, we show that a proportional-share unchoker yields faster downloads against BitTorrent and BitTyrant clients, and that underreporting pieces yields prolonged neighbor interest

An Analysis of incentives mechanisms and evaluation on BitTorrent

Since the first peer-to-peer communities appeared, their number of users has increased considerably owing to the benefits they offer compared to their alternative architectures in the sharing and distribution of multimedia content. However, due to its distributed nature, they can suffer an important problem of misuse: free-riding. Free-riding consists on users consuming resources without contributing to the system. Such behaviour not only is not fair for the rest of the users, but also threatens the success of this type of nets. With the motivation to avoid free-riding, the mechanisms of incentives were born. They provide the system with a method to motivate the nodes and make them share their resources with the other users. In one word, they provide the net with the needed fairness to achieve a good performance for all users. This thesis is organised in two main parts. In the first part there is a comprehensive study of the state of the art regarding the incentive mechanisms, resulting in a classification depending on the characteristics of the studied algorithms. That study provides the reader with a first sight of the strengths and weaknesses of each algorithm. In the second part there is a test scenario based in the virtualization of machines that was useful to evaluate empirically some of the studied algorithms. Finally, a series of experiments were carried out in order to compare some characteristics of these algorithms and thus verify or deny the conclusions resulted in the study of the state of the art

When Money Grew on Trees: Lucy v. Zehmer and Contracting in a Boom Market

This Article revisits Lucy v. Zehmer, a 1950s Virginia Supreme Court ruling that has become a staple in most contracts courses in American law schools. The colorful facts are well known to nearly all law students: Lucy and Zehmer met one evening in December 1952 at a restaurant in Dinwiddie, Virginia, and, following several drinks and much verbal banter, Zehmer wrote a contract on a restaurant bill, in which he agreed to sell his farm to Lucy for $50,000. Zehmer later insisted that he had been intoxicated and had thought the entire matter was a joke. He testified that he had been high as a Georgia pine and merely bluffing to try to get Lucy to admit that he did not actually have$50,000. Upholding the contract, the court ruled that regardless of Zehmer’s intent, his outward behavior could reasonably be construed to suggest that he had been serious. The court thus invoked what is known as the objective theory of contract formation. Our findings suggest that the court misinterpreted the contractual setting surrounding that December evening in 1952. Our research uncovers several discoveries: (1) Lucy, acting as a middleman for southern Virginia’s burgeoning pulp-and-paper industry, sought the Ferguson farm for its rich timber reserves; (2) Lucy was one of scores of aggressive timber middlemen in the region who eagerly sought valuable timberland and prompted a chaotic landgrab, leaving a wake of shady transactions and colorful litigation; and (3) within eight years of winning injunctive relief from the Virginia Supreme Court and purchasing the Ferguson farm from Zehmer for $50,000, Lucy earned approximately$142,000 from selling the land and its natural resources. These findings call into question the court’s assertion that $50,000 was a fair price, its conclusion that Zehmer’s actions indicated contractual intent, and its confidence that the objective method captured the relevant background in which Lucy’s and Zehmer\u27s exchange took place. More generally, these findings suggest that conclusions reached by the objective method are highly dependent on both the facts that are retold and the context in which those facts occurred, and that historical analysis can meaningfully illustrate the limits of legal doctrines

Survival in the e-conomy: 2nd Australian information warfare & security conference 2001

This is an international conference for academics and industry specialists in information warfare, security, and other related fields. The conference has drawn participants from national and international organisations

The Daily Texan

Texas Student Medi

The NEBLINE, April 2007

Contents: UNL Extension Programs Have Improved Termite Treatments in Nebraska 2007 Perennial Plant of the Year Gardening Trends in 2007 Easter Lily Care Spring is a Good Time to Begin Herb Gardening “Management of Small Ponds” Clinic, April 17 Arbor Day and Tree Planting are Nebraska Traditions Container Gardening Controlling Nuisance Weeds in Your Farm Pond Teff – A New Annual Forage Grass Simplified Hand-Held Sprayer Calibration Cost of Pumping Water for Domestic and Acreage Needs Commercial Pesticide Applicator Initial Training, April 19 It’s Springtime: Watch for Signs of Termites Termite Workshops for Homeowners in May What’s Bugging You? Spring Cleaning? Take Advantage of Household Hazardous Waste Collections Tips to Encourage Nesting Birds Don’t be “Myth”-Led by These Food Safety Myths Easter Celebration Vegetables: More than Just a “Side Dish” Tangy Raspberry Salad Recipe President’s Notes — Alice’s Analysis Household Hints: Removing Easter Egg Dye Stains First Shred Day in Lincoln, April 28 FCE News & Events Teens & Cell Phones — Cameras, Internet and Music TV Turnoff Week, April 23–29 Roberta Sandhorst Spring Rabbit Show Free Kiwanis Karnival, April 14 2007 Lancaster County Fair Speech & PSA Contest Teen Council Community Service Project Stampede Results All Riding Skills Level Tests Must be Done in Group Testings Tornado Awareness – A Guide to Survival Your 4-H Talent Can Lead to an Exciting Career! Pioneer Farm Family Award Applications Due May 1 The Nebraska LEAD Program Extension Calendar Lock-In Gives 4-H Teens Leadership Experience Enter an Exhibit at the County Fair Watch Chicks Hatch on Egg Cam! U.S. Drought Monitor Map Resource Conservation Guide Special Pullout Sectio