2 resultados para principals
em Duke University
Resumo:
Secure Access For Everyone (SAFE), is an integrated system for managing trust
using a logic-based declarative language. Logical trust systems authorize each
request by constructing a proof from a context---a set of authenticated logic
statements representing credentials and policies issued by various principals
in a networked system. A key barrier to practical use of logical trust systems
is the problem of managing proof contexts: identifying, validating, and
assembling the credentials and policies that are relevant to each trust
decision.
SAFE addresses this challenge by (i) proposing a distributed authenticated data
repository for storing the credentials and policies; (ii) introducing a
programmable credential discovery and assembly layer that generates the
appropriate tailored context for a given request. The authenticated data
repository is built upon a scalable key-value store with its contents named by
secure identifiers and certified by the issuing principal. The SAFE language
provides scripting primitives to generate and organize logic sets representing
credentials and policies, materialize the logic sets as certificates, and link
them to reflect delegation patterns in the application. The authorizer fetches
the logic sets on demand, then validates and caches them locally for further
use. Upon each request, the authorizer constructs the tailored proof context
and provides it to the SAFE inference for certified validation.
Delegation-driven credential linking with certified data distribution provides
flexible and dynamic policy control enabling security and trust infrastructure
to be agile, while addressing the perennial problems related to today's
certificate infrastructure: automated credential discovery, scalable
revocation, and issuing credentials without relying on centralized authority.
We envision SAFE as a new foundation for building secure network systems. We
used SAFE to build secure services based on case studies drawn from practice:
(i) a secure name service resolver similar to DNS that resolves a name across
multi-domain federated systems; (ii) a secure proxy shim to delegate access
control decisions in a key-value store; (iii) an authorization module for a
networked infrastructure-as-a-service system with a federated trust structure
(NSF GENI initiative); and (iv) a secure cooperative data analytics service
that adheres to individual secrecy constraints while disclosing the data. We
present empirical evaluation based on these case studies and demonstrate that
SAFE supports a wide range of applications with low overhead.
Resumo:
The current era of American Christianity marks the transition from a Western, white-dominated U.S. Evangelicalism to an ethnically diverse demographic for evangelicalism. Despite this increasing diversity, U.S. Evangelicalism has demonstrated a stubborn inability to address the entrenched assumption of white supremacy. The 1970s witnessed the rise in prominence of Evangelicalism in the United States. At the same time, the era witnessed a burgeoning movement of African-American evangelicals, who often experienced marginalization from the larger movement. What factors prevented the integration between two seemingly theologically compatible movements? How do these factors impact the challenge of integration and reconciliation in the changing demographic reality of early twenty-first Evangelicalism?
The question is examined through the unpacking of the diseased theological imagination rooted in U.S. Evangelicalism. The theological categories of Creation, Anthropology, Christology, Soteriology, and Ecclesiology are discussed to determine specific deficiencies that lead to assumptions of white supremacy. The larger history of U.S. Evangelicalism and the larger story of the African-American church are explored to provide a context for the unique expression of African-American evangelicalism in the last third of the twentieth century. Through the use of primary sources — personal interviews, archival documents, writings by principals, and private collection documents — the specific history of African-American evangelicals in the 1960s and 1970s is described. The stories of the National Black Evangelical Association, Tom Skinner, John Perkins, and Circle Church provide historical snapshots that illuminate the relationship between the larger U.S. Evangelical movement and African-American evangelicals.
Various attempts at integration and shared leadership were made in the 1970s as African-American evangelicals engaged with white Evangelical institutions. However, the failure of these attempts point to the challenges to diversity for U.S. Evangelicalism and the failure of the Evangelical theological imagination. The diseased theological imagination of U.S. Evangelical Christianity prevented engagement with the needed challenge of African American evangelicalism, resulting in dysfunctional racial dynamics evident in twenty-first century Evangelical Christianity. The historical problem of situating African American evangelicals reveals the theological problem of white supremacy in U.S. Evangelicalism.