As more complex security services have been added to today's Internet, it becomes increasingly difficult to quantify their vulnerability to compromise. The concept of "attack surface" has emerged in recent years as a measure of such vulnerabilities, however systematically quantifying the attack surfaces of networked systems remains an open challenge. In this work we propose a methodology to both quantify the attack surface and visually represent semantically different components (or resources) of such systems by identifying their dependencies. To illustrate the efficacy of our methodology, we examine two real Internet standards (the X.509 CA verification system and DANE) as case studies. We believe this work represents a first step towards systemically modeling dependencies of (and interdependencies between) networked systems, and shows the usability benefits from leveraging existing services.

The DNS Security Extensions (DNSSEC) arguably make DNS the first core Internet system to be protected using public key cryptography. The success of DNSSEC not only protects the DNS, but has generated interest in using this secured global database for new services such as those proposed by the IETF DANE working group. However, continued success is only possible if several important operational issues can be addressed. For example, .gov and .arpa have already suffered misconfigurations where DNS continued to function properly, but DNSSEC failed (thus, orphaning their entire subtrees in DNSSEC). Internet-scale verification systems must tolerate this type of chaos, but what kind of verification can one derive for systems with dynamism like this? In this paper, we propose to achieve robust verification with a new theoretical model, called Public Data, which treats operational deployments as Communities of Trust (CoTs) and makes them the verification substrate. Using a realization of the above idea, called Vantages, we quantitatively show that using a reasonable DNSSEC deployment model and a typical choice of a CoT, an adversary would need to be able to have visibility into and perform on-path Man-in-the-Middle (MitM) attacks on arbitrary traffic into and out of up to 90 percent of the all of the Autonomous Systems (ASes) in the Internet before having even a 10 percent chance of spoofing a DNSKEY. Further, our limited deployment of Vantages has outperformed the verifiability of DNSSEC and has properly validated its data up to 99.5 percent of the time.

The era of free IPv4 address allocations has ended and the grey market in IPv4 addresses is now emerging. This paper argues that one cannot and should not try to regulate who sells addresses and at what price, but one does need to provide some proof of ownership in the form of resource certification. In this paper we identify key requirements of resource certification, gained from both theoretical analysis and operational history. We further argue these requirements can be achieved by making use of the existing reverse DNS hierarchy, enhanced with DNS Security. Our analysis compares reverse DNS entries and BGP routing tables and shows this is both feasible and achievable today; an essential requirement as the grey market is also emerging today and solutions are needed now, not years in the future.

In this paper, we examine changes in Internet inter-domain traffic demands and interconnection policies. We analyze more than 200 Exabytes of commercial Internet traffic over a two year period through the instrumentation of 110 large and geographically diverse cable operators, international transit backbones, regional networks and content providers. Our analysis shows significant changes in inter-AS traffic patterns and an evolution of provider peering strategies. Specifically, we find the majority of inter-domain traffic by volume now flows directly between large content providers, data center / CDNs and consumer networks. We also show significant changes in Internet application usage, including a global decline of P2P and a significant rise in video traffic. We conclude with estimates of the current size of the Internet by inter-domain traffic volume and rate of annualized inter-domain traffic growth.