Disclosed herein are systems and methods that allow for secure access to websites and web-based applications and other resources available through the browser. Also described are systems and methods for secure use and retention of user credentials, as well as methods for dynamic authentication of users and integrity checking of service providers in online environments. Thus, described in the present specification are systems and methods for constructing and destroying private, secure, browsing environments (a secure disposable browser), insulating the user from the threats associated with being online for the purposes of providing secure, policy-based interaction with online services.