Computing systems designed using reconfigurable hardware are increasingly composed using a number of different Intellectual Property (IP) cores, which are often provided by third-party vendors that may have different levels of trust. Unlike traditional software where hardware resources are mediated using an operating system, IP cores have fine-grain control over the underlying reconfigurable hardware. To address this problem, the embedded systems community requires novel security primitives that address the realities of modern reconfigurable hardware. In this work, we propose security primitives using ideas centered around the notion of "moats and drawbridges." The primitives encompass four design properties: logical isolation, interconnect traceability, secure reconfigurable broadcast, and configuration scrubbing. Each of these is a fundamental This research was funded in part by National Science Foundation Grant CNS-0524771, NSF Career Grant CCF-0448654, and the SMART Defense Scholarship for Service. Authors' addresses: T. Huffmire, T. Levin, T. Nguyen, and C. Irvine, Department of Computer Science, Naval Postgraduate School, Monterey, CA 93943; email: {tdhuffmi, televin, tdnguyen, irvine}@nps.edu; B. Brotherton, Special Technologies Laboratory, Santa Barbara, CA 93111; email: brett.brotherton@gmail.com; G. Wang, Intuit, San Diego, CA 92122; email: Gang Wang@ intuit.com; T. Sherwood, Department of Computer Science, University of California, Santa Barbara, CA 93106; email: sherwood@cs.ucsb.edu; R. Kastner, Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA 92093; email: kastner@cs.ucsd.edu. c 2010 Association for Computing Machinery. ACM acknowledges that this contribution was authored or co-authored by a contractor or affiliate of the [U.S.] Government. As such, the Government retains a nonexclusive, royalty-free right to publish or reproduce this article, or to allow others to do so, for Government purposes only. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or direct commercial advantage and that copies show this notice on the first page or initial screen of a display along with the full citation. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, to redistribute to lists, or to use any component of this work in other works requires prior specific permission and/or a fee. Permissions may be requested from Publications Dept., ACM, Inc., 2 Penn Plaza, Suite 701, New York, NY 10121-0701 USA, fax +1 (212) operation with easily understood formal properties, yet they map cleanly and efficiently to a wide variety of reconfigurable devices. We carefully quantify the required overheads of the security techniques on modern FPGA architectures across a number of different applications.