This glossary of common security terms has been extracted from NIST Federal Information Processing Standards (FIPS), the Special Publication (SP) 800 series, NIST Interagency Reports (NISTIRs), and from the Committee for National Security Systems Instruction 4009 (CNSSI-4009). The glossary includes most of the terms in the NIST publications. It also contains nearly all of the terms and definitions from CNSSI-4009. The glossary provides a central resource of terms and definitions most commonly used in NIST information security publications and in CNSS information assurance publications. For a given term, we do not include all definitions in NIST documents – especially not from the older NIST publications. Since draft documents are not stable, we do not refer to terms/definitions in them. Each entry in the glossary points to one or more source NIST publications, and/or CNSSI-4009, and/or supplemental sources where appropriate. A list of the supplemental (non-NIST) sources may be found on pages 221-222. As we are continuously refreshing our publication suite, terms included in the glossary come from our more recent publications. Why buy an eBook when you can download a PDF for free? First you gotta find it and make sure it’s the latest version, not always easy. It’s much more cost-effective to just order the latest version from Amazon.com Unlike a PDF, this eBook allows easy page navigation because we bookmarked the Chapters and Appendices. (Don’t judge based on the free sample because that functionality is not activated on the free sample.) Once you buy a copy you will see how easy it is to get to the information you seek - fast. Also, if you turn on Text-to-Speech, your kindle will read the book out loud for you! This material is published by 4th Watch Publishing Co. We publish tightly-bound, full-size books at 8 ½ by 11 inches, with glossy covers. 4th Watch Publishing Co. is a Service Disabled Veteran Owned Small Business (SDVOSB) and is not affiliated with the National Institute of Standards and Technology. A full copy of over 300 cybersecurity standards is loaded on our CyberSecurity Standards Library DVD which is available at Amazon.com. And, if you need to look up an acronym or the definition of a word, just go to the Cyber Dictionary.