Verifiable Boosted Tree Ensembles

Verifiable learning advocates for training machine learning models amenable to efficient security verification. Prior research demonstrated that specific classes of decision tree ensembles -- called large-spread ensembles -- allow for robustness verification in polynomial time against any norm-based attacker. This study expands prior work on verifiable learning from basic ensemble methods (i.e., hard majority voting) to advanced boosted tree ensembles, such as those trained using XGBoost or LightGBM. Our formal results indicate that robustness verification is achievable in polynomial time when considering attackers based on the $L_\infty$-norm, but remains NP-hard for other norm-based attackers. Nevertheless, we present a pseudo-polynomial time algorithm to verify robustness against attackers based on the $L_p$-norm for any $p \in \mathbb{N} \cup \{0\}$, which in practice grants excellent performance. Our experimental evaluation shows that large-spread boosted ensembles are accurate enough for practical adoption, while being amenable to efficient security verification.Comment: 15 pages, 3 figure

Common Law with Uncommon Regulations: the influence of legal tradition on campaign finance regimes

Americans spent $11.4 billion in their last federal election cycle but collectively, the United Kingdom and Canada only spent a little over$550 million in their last general elections. These three states have similarities in democratic governance, economic legacy, and common law legal system grouping but how did they become so separated in campaign finance regulations? Prior research in the field of international comparative campaign finance law is limited and primarily focuses on using political theories to describe the movement of laws toward deregulation or regulation. This research seeks to find what influences the creation, preservation, and deregulation of campaign finance laws in these affluent Western states. Focusing on legal tradition, this research analyses the historical, institutional, and cultural components of law and society in each respective state. In tandem, this research uses textual analysis to look at every legally binding federal campaign finance law and judicial decision for each state is studied to see how legal tradition has affected trends of regulation or deregulation throughout the decades. Through this framework, this study finds that legal tradition has influenced three unique outcomes for the level of regulation in each state’s election finance regime. The United States’ legal tradition has invested considerable power in the judiciary, which has severely limited American legislators\u27 ability to regulate elections. This judicial intervention and the legal tradition surrounding its power has resulted in severe deregulation of election finance laws. In the United Kingdom, a legal tradition of parliamentary sovereignty, an unwritten constitution, and a legal history of comity between legislators and the judiciary has resulted in a series of regulatory statutes that have not been weakened by other constitutional actors. Lastly, Canada’s legal tradition tells a story of political adversarial gain with both written and unwritten constitutions, parliamentary sovereignty, and weakened judiciary that has culminated in a back and forth of regulated and deregulated laws based on the leading majority political party. These states all operate in the common law system but if we look at them broadly in just that category of organization, we are unable to note the differences that have influenced diverging trends in regulating campaign finance regimes. This research is the first in the field of comparative campaign finance legal studies to emphasize the importance of analyzing the cultural, historical, and institutional factors of each respective state. Without this lens, we are unable to understand law as a social phenomenon and how these campaign finance laws are a part of a bigger picture that has been in the making for decades. Without this all-encompassing view of legal tradition, there is no way to determine if a law will stand institutional interventions or the test of time

Managing the Unmanageable: A Brief Accounting of a Special Master’s Thirty Years of Experience in Complex Litigation

Managing an efficient, but fair, pretrial process in a large and complex case has always been a challenge. With the advent of electronic communications and the corresponding explosion of privilege claims, this challenge has become significantly more difficult. Indeed, it is not uncommon for corporate parties to assert tens of thousands, if not hundreds of thousands, of privilege claims. Furthermore, the resolution of these privilege questions is often compounded by difficult choice of law questions that can have the result of different substantive principles being applied to identical discovery demands originating in different jurisdictions. Additionally, before addressing the increasingly voluminous and complicated privilege question, many parties often raise other discovery issues that must be resolved before depositions and document production can proceed in a meaningful fashion. With this increase in the numbers of claims, the privilege resolution process has become significantly more costly. The initial costs in locating documents, assessing their privilege character, preparing privilege logs, and developing evidence to substantiate each claim can be overwhelming. Compounding this effort is metadata underlying most electronic documents that may also contain privileged materials. These enormous costs are further increased when special masters must be appointed to examine the millions of pages of materials that active judges have neither the time nor the paralegal resources to coordinate, review, and individually rule upon. Through these experiences as a judicial officer over the past thirty years, a number of novel procedures have been employed that proved to be effective case management tools. They saved valuable time and avoided unnecessary expenses while still accommodating the needs of the litigants in preparing their cases for trial on an expedited basis. Therefore, I offer a brief accounting of these procedures and processes in the hope that others might benefit from those experiences

Managing the Unmanageable: A Brief Accounting of a Special Master’s Thirty Years of Experience in Complex Litigation

Managing an efficient, but fair, pretrial process in a large and complex case has always been a challenge. With the advent of electronic communications and the corresponding explosion of privilege claims, this challenge has become significantly more difficult. Indeed, it is not uncommon for corporate parties to assert tens of thousands, if not hundreds of thousands, of privilege claims. Furthermore, the resolution of these privilege questions is often compounded by difficult choice of law questions that can have the result of different substantive principles being applied to identical discovery demands originating in different jurisdictions. Additionally, before addressing the increasingly voluminous and complicated privilege question, many parties often raise other discovery issues that must be resolved before depositions and document production can proceed in a meaningful fashion. With this increase in the numbers of claims, the privilege resolution process has become significantly more costly. The initial costs in locating documents, assessing their privilege character, preparing privilege logs, and developing evidence to substantiate each claim can be overwhelming. Compounding this effort is metadata underlying most electronic documents that may also contain privileged materials. These enormous costs are further increased when special masters must be appointed to examine the millions of pages of materials that active judges have neither the time nor the paralegal resources to coordinate, review, and individually rule upon. Through these experiences as a judicial officer over the past thirty years, a number of novel procedures have been employed that proved to be effective case management tools. They saved valuable time and avoided unnecessary expenses while still accommodating the needs of the litigants in preparing their cases for trial on an expedited basis. Therefore, I offer a brief accounting of these procedures and processes in the hope that others might benefit from those experiences