Flow Control
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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.


In all computer systems involving any sort of program and user interaction. Flow control forms one of the most critical functions. In distributed computing, controlling the flow of information between separate systems that may or may not be trusted poses very real and specific security challenges. Protection against malware, such as spyware and Trojans means that the network traffic that carries this malicious payload is not allowed to enter the network. Assuming of course, that it can be appropriately identified and blocked at the point of entry.

By controlling the flow of information or data, several threats to software can be mitigated and delivery of valid messages guaranteed. Enforcing security policies, which must themselves be properly constructed and placed under strict configuration management, which concern how information can flow to, and from an application, independent of code-level security protection mechanisms. This can assist implementation of protection. When the code itself cannot be trusted. Other elements such as firewalls, proxies, middleware and queuing technologies can be used to control the rate of data transmission and allow or disallow the flow of information across trust boundaries.

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