Publication Date

Fall 2017

Degree Type

Master's Project


Computer Science


Information flow analysis is the study of mechanisms by which developers may protect sensitive data within an ecosystem containing untrusted third-party code. Secure multi-execution is one such mechanism that reliably prevents undesirable information flows, but a programmer’s use of secure multi-execution is itself challenging and prone to error. Faceted values have been shown to provide an alternative to secure multi-execution which is, in theory, functionally equivalent. The purpose of this work is to show that the theory holds in practice by implementing usable faceted values in JavaScript via source code transformation. The primary contribution of this project is to provide a library that makes these transformations possible in any standard JavaScript runtime without requiring native support. We build a pipeline that takes JavaScript code with syntactic support for faceted values and, through source code transformation, produces platform-independent JavaScript code containing functional faceted values. Our findings include a method by which we may optimize the use of faceted values through static analysis of the program’s information flow.