  The Internet Protocol (IP) is the lifeblood of the modern Internet. Its
simplicity and universality have fueled the unprecedented and lasting global
success of the current Internet. Nonetheless, some limitations of IP have been
emerging in recent years. Its original design envisaged supporting perhaps tens
of thousands of static hosts operating in a friendly academic-like setting,
mainly in order to facilitate email communication and remote access to scarce
computing resources. At present IP interconnects billions of static and mobile
devices (ranging from supercomputers to IoT gadgets) with a large and dynamic
set of popular applications. Starting in mid-1990s, the advent of mobility,
wirelessness and the web substantially shifted Internet usage and communication
paradigms. This accentuated long-term concerns about the current Internet
architecture and prompted interest in alternative designs.
  The U.S. National Science Foundation (NSF) has been one of the key supporters
of efforts to design a set of candidate next-generation Internet architectures.
As a prominent design requirement, NSF emphasized "security and privacy by
design" in order to avoid the long and unhappy history of incremental patching
and retrofitting that characterizes the current Internet architecture. To this
end, as a result of a competitive process, four prominent research projects
were funded by the NSF in 2010: Nebula, Named-Data Networking (NDN),
MobilityFirst (MF), and Expressive Internet Architecture (XIA). This paper
provides a comprehensive and neutral analysis of salient security and privacy
features (and issues) in these NSF-funded Future Internet Architectures. It
also compares the four candidate designs with the current IP-based architecture
and discusses similarities, differences, and possible improvements.
