Kimberly C. Claffy (kc claffy) Professional Biography


kc has been studying various Internet research topics since 1990, spanning topology, routing, traffic, economics, and policy. In 1993 she co-authored her first paper on proposed traffic management approaches to deal with congestion, in a paper entitled Mitigating the Coming Internet Crunch. In 1994 she published her doctoral dissertation on Internet traffic characterization, using public NSFNET traffic data. She established her research career, and a leading organization, in pursuit of rigorous analysis of the best available empirical data to inform our understanding of the Internet as a complex system. This pursuit often required developing measurement instrumentation to gather data on the public Internet infastructure. A central focus of her contribution is infrastructure for data collection, curation, management, and sharing, including governance models and ethical frameworks to support study of the Internet’s core infrastructure, focused on the health and integrity of the Internet routing, addressing, and naming systems.

kc has published 296 papers, most recently on studies of security, stability, and resilience (SSR) properties of the subsystems that constitute the Internet’s fundamental plumbing: IP addressing, DNS, and interdomain (BGP) routing. Each of these systems is characterized by critical flaws that leave the Internet vulnerable to attacks. Her commitment to longitudinal measurement infrastructure projects allowed completion of the most comprehensive analysis thus far of one such fundamental architectural vulnerability: IP address spoofing. This analysis included an assessment deployment of IP source address validation on the Internet since 2005, including approaches taken to encourage remediation and the challenges of evaluating their impact. In 2018 she began a new cybersecurity research project in collaboration with Dutch colleagues (co-funded by U.S. and Dutch governments) that aims to comprehensively characterize DDoS attacks targeting the DNS, and vulnerabilities that impede resilience of the DNS in the face of such DDoS attacks. This project led to an ongoing collaboration with UCSD’s CSE department to investigate the prevalence, persistence, and risks of several types of DNS misconfigurations

Data Sharing

Since inception, kc has led CAIDA to release 42 software packages (32 currently supported). The complete list (sortable) is available at CAIDA currently offers over 60 datasets listed (sortable) at CAIDA maintains three measurement infrastructures for use by both internal and external non-UCSD researchers: Ark, backbone monitors, and the UCSD Network Telescope.

From 2018-2021, over 1.2 million unique visitors browsed CAIDA main website, and CAIDA granted access to restricted data to 1426 vetted researchers (of 2312 requesting users):

  • 526 of those are US academic or government researchers,
  • 223 are academics from China,
  • 63 from Germany,
  • 52 from India,
  • 51 from UK,
  • 47 from Brazil.

Over the same period approximately 150,000 users downloaded (330 TB) of public CAIDA data. CAIDA’s data has been used for more than 2372 scientific papers (

Expert testimony and advice

kc has given testimony and advice to FCC, DHS, NSF, DOE, FTC, OSTP, NSA, DARPA, and NIST, regarding how the public sector can best support measurable progress on our scientific understanding of current and future national information infrastructure. She has given invited talks on Internet topics at NANOG, ARIN, CENIC, QUILT, OECD, ISOC, IBM, NLR, Google, CENIC, Usenix, LISA, AUUG, RIPE, Pew, Terena, Stanford, Harvard, and Columbia.

Community Service

kc has presented at Internet operational and policy fora (e.g, NANOG, ARIN, IETF as needed) and many government agencies (DHS, NIST, NCS/DISA, DARPA, FCC, FTC, OSTP, NSA, GAO, NSF) on a variety of topics related to the past, present and future of the Internet, and often to share and discuss research directions and results of CAIDA activities with implications for the future. She generally leads 2-3 workshops per year (see list of workshop reports on Caida Catalog). kc served on the NANOG (North American Network Operators Group) program committee for ten years (1996-2005), and also served as a member of two of ICANN’s three primary advisory committees: SSAC (Security and Stability Advisory Committee) and RSSAC (Root Server Selection Advisory Committee). For over 3 years she served on Internet2’s Research Advisory Council.

kc has served on program committees, published papers, or both, in all of the main conferences related to empirical Internet science: Internet Measurement Conference (IMC), Passive and Active Measurement Conference, ACM SIGCOMM, Infocom, IEEE/ACM Transactions on Networking, ACM Computer Communications Review, Traffic Measurement and Analysis (TMA), IEEE S&P Magazine. From 2004-2008 she served on the Editorial Board of IEEE Internet Computing.


  • Internet measurement infrastructure, data collection, and privacy-respecting data sharing;
  • Measuring and mapping attributes of the Internet related to infrastructure security and stability;
  • Future Internet Architecture research;
  • Ethics of information technology research

Recent Accomplishments (2018 - 2021)

  • 28 peer-reviewed journal/conference publications (1 first-author, 26 senior- author)
  • 8 workshop reports including for 2021 WOMBIR workshop requested by NSF
  • 11 grants totaling ~$9M to UCSD: 6 as sole PI, 2 with co-PI(s), and 3 as co-PI
  • Mentored two Research Scientists to next jobs (AWS and GaTech)
  • Two new postdocs, and mentored to next jobs (Cloudflare and SDSC Research Scientist)
  • Mentored 3 Phd students(co-advising1 UCSD CSE PhD),3 Masters and 24 undergrads
  • Internet Hall of Fame, 2019
  • Helped to launch non-profit foundation Amateur Radio and Digital Communications
  • Served on two ICANN independent review committees
  • Led massive upgrade of CAIDA’s web site (after ~15 years)
  • Led develoment and release of (rich context) Internet Science Resource Catalog
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