Security Development Lifecycle (SDL)
Security Development Lifecycle (SDL)

This is the fourth course in Domain 3 of the CSSLP certification and covers the essential ideas, concepts, and principles that you need to take into account when building secure software.

Learning Objectives

  • Understand the process and controls available to secure your software
  • Learn about the main security technologies available

Intended Audience

This course is intended for anyone looking to develop secure software as well as those studying for the CSSLP certification.


Any experience relating to information security would be advantageous, but not essential. All topics discussed are thoroughly explained and presented in a way allowing the information to be absorbed by everyone, regardless of experience within the security field.


So let's revisit the Security Development Lifecycle as a subset of the Software Development Life Cycle, which itself is a subset of the system lifecycle or SLC. So the SDL as we're going to treat it here, rests on the principles, and there are a number of other fundamental design objectives for the planned product. We want it to be secure by design. We want it also to be secure by default. In other words, it goes in as secure by design, it's secure by default or deny by default, and as needs arise, we will open it up gradually, but it begins out in a fully self-protecting mode.

We have to recognize that implementation oftentimes introduces errors that may not have been existing in the software prior to implementation. There are many examples of implementation flaws and failures that have produced faults and problems in software that had been properly designed, basically the implementation on doing all of the good work we did before. So what we need to do is make sure that it's built in such a way that deployment will increase the security, the privacy, the operability, and the control that we have built into the product rather than diminish it. And then, of course, it has to be secure in communications. Many laws now refer to secure for the various data states in motion, at rest, or in use as safe harbor, and the communications are certainly fundamental to that, and so we need to be sure that these areas, design, default, deployment, and communications, are properly understood and accounted for.

About the Author
Learning Paths

Mr. Leo has been in Information System for 38 years, and an Information Security professional for over 36 years.  He has worked internationally as a Systems Analyst/Engineer, and as a Security and Privacy Consultant.  His past employers include IBM, St. Luke’s Episcopal Hospital, Computer Sciences Corporation, and Rockwell International.  A NASA contractor for 22 years, from 1998 to 2002 he was Director of Security Engineering and Chief Security Architect for Mission Control at the Johnson Space Center.  From 2002 to 2006 Mr. Leo was the Director of Information Systems, and Chief Information Security Officer for the Managed Care Division of the University of Texas Medical Branch in Galveston, Texas.


Upon attaining his CISSP license in 1997, Mr. Leo joined ISC2 (a professional role) as Chairman of the Curriculum Development Committee, and served in this role until 2004.   During this time, he formulated and directed the effort that produced what became and remains the standard curriculum used to train CISSP candidates worldwide.  He has maintained his professional standards as a professional educator and has since trained and certified nearly 8500 CISSP candidates since 1998, and nearly 2500 in HIPAA compliance certification since 2004.  Mr. leo is an ISC2 Certified Instructor.

Covered Topics