1. A system for securing a host computing device, comprising: a central processing unit; a first component that: receives a stream, the stream containing a security policy; and for each of a set of two or more security engines, prepares a first portion of the security policy relating to a first security engine of the set of two or more security engines; prepares a second portion of the security policy relating to a second security engine of the set of two or more security engines; communicates the prepared portions of the security policy to the first and second security engines of the set of two or more security engines; if the first security engine of the set two or more security engines indicates a failure after receiving the first prepared portion of the security policy but the second security engine of the set of two or more security engines does not indicate a failure after receiving the second prepared portion of the set security policy, causes the second security engine to roll back the second prepared portion of the security policy; and one of the security engines of the set that, when none of the security engines indicates a failure after receiving the prepared portion of the security policy, enforces the portion of the security policy it received, wherein the first component and all security engines operate at the host computing device within a single operating system.