Using Large-Scale Empirical Methods to Understand Fragile Cryptographic Ecosystems

Cryptography is a key component of the security of the Internet.
Unfortunately, the process of using cryptography to secure the Internet is
fraught with failure. Cryptography is often fragile, and a single mistake can
have devastating consequences on security. This fragility is further
complicated by the distributed and diverse nature of the Internet, where
rapid and wholesale changes are impossible to deploy. As a result, the
cryptography used to secure the Internet is a vast array of algorithms,
protocols, implementations and parameters that reflects the diverse nature of
the Internet.

This dissertation shows how to use empirical methods from large-scale network
measurement to study how cryptography is deployed on the Internet, and shows
this methodology can gain insights into fragile cryptographic ecosystems that
are not possible without an empirical approach.