1. A method of testing a web application, wherein a web application is a program that operates on a server and interacts with clients that access the program over a network, wherein further the web application accepts parameters that define results generated from the web application, the method comprising: determining which web application uniform resource identifiers (“URIs”) are used to access each of a subset of web applications on a system, each web application being operable to accept parameters that define results generated from the web application; selecting, for each web application of the subset of web applications, a subset of less than all of the URIs for the web application, wherein the subset is selected at least in part randomly and independently of the order the web application URIs were generated; and for each web application of the subset of web applications, executing electronic interactions with the web application, comprising: (a) performing a security scan on a first URI of the subset of URIs for the web application; (b) comparing locality-sensitive hash (“LSH”) signatures of responses to the URI of the subset of URIs for the web application; (c) determining if a difference between the responses exceed a threshold, the threshold used to establish a minimum difference between the responses; and (d) performing a security scan on a second URI of the subset of URIs for the web application when the difference between the responses exceeds the threshold.