Security Systems Development Life Cycle
When designing information systems there are logical phases which must be considered in order to achieve maximum efficiency and effectiveness throughout the organization in every role. Throughout the six phases of the systems development life cycle (SDLC) it becomes imperative to ensure that security is integrated with each aspect of the platform. When building a security project, the same phases of the SDLC can be adapted to suite. The security systems development life cycle (SecSDLC) shares similarities with the SDLC, however the intent and activities are different. The purpose of this paper is to review and explain the phases of the SecSDLC, discussing the differences between the SDLC, and applicable certifications.
Investigation
In this phase, the project scope and goals are defined upper management. They provide the process methodologies, expected outcomes, project goals, the budget, and any other relevant constraints. “Frequently, this phase begins with an enterprise information security policy (EISP), which outlines the implementation of a security program within the organization.” (Whitman & Mattord, 2012, p. 26). Teams are organized, problems analyzed, and any additions to scope are defined, discussed, and integrated into the plan. The final stage is a feasibility study to determine if corporate resources are available to support the endeavor. The primary difference from the traditional SDLC is that management defines the project details. In the SDLC the business problems to be solved are researched and developed by the project team.
Analysis
In this phase, the documents gathers in phase one are studied and a preliminary analysis of the existing security polices is conducted. At the same time, the current threat landscape is evaluated and documented, as are the controls in place to manage or mitigate these threats. Included at this stage is a review of legal considerations that must be integrated into the security plan. The modern global threat landscape is such that any business, small or large, is susceptible to attack from a third party, whether it be directly or indirectly. Certain industries have strict requirements on how data is to be stored, shared, or manipulated. Standards such as HIPPA, NIST, PCI-DSS, the ISO27001 standard, and others provide guidelines for an organization to be certified as complaint with established processes and methods. Some industries require these certifications in order for a company to conduct business in that sector. Understanding state legislations with regards to what computer activities are deemed illegal is vital to the overall plan execution and sets the baseline for the types of security technologies that can be implemented across the enterprise. The risk assessment in this phase identifies, assesses, and evaluates the threats to the organization’s security and data. The final step in this phase is to document the findings and update the feasibility analysis. The main differences between the SDLC at this phase include the examination of legal issues, relevant standards based on the segment within which the company is situated, the completion of a formal risk analysis, and the review of the threat landscape and their underlying controls. Those aspects are specifically unique to the SecSDLC. While considering security within every phase of the SDLC is vital, the focus and scope of security considerations are vastly different compared to the SecSDLC which focuses solely on the security aspect of an information systems.
Logical Design
With the SecSDLC, this phase creates and develops the blueprints for information security across the enterprise. Key policies are examined and implemented, and an incident response plan is generated to ensure business continuity, define what steps are taken when an attack occurs, and what is done to recover from a disastrous event. Similar to the SDLC, applications, data support, and structures are selected considering multiple solutions in an approach to managing threats. Unique to the SecSDLC is the detail involved with securing the SDLC core concepts by analyzing the system security environment, functional security requirements, assurance that the security system developed will perform as expected, cost considerations with regards to hardware, software, personnel, and training, documentation of security controls that are planned or in place, security control development, use case tests and test evaluation methods. The concepts and best practices detailed by the NIST can be seen as a guide throughout this phase with regards to system hardening and expected security measures to be taken to ensure end-to-end security across the enterprise. Project documents are again updated, and as with previous phases, the feasibility study is revisited to determine whether or not to continue the project, and/or whether or not to outsource the project.
Physical Design
The fourth phase of the SecSDLC evaluates the information security technologies needed to support the created blueprint and generate alternative solutions, which dictate the final system design. Technologies evaluated in the logical design phase are the best are selected to support the solutions developed, whether they are custom built or off-the-shelf. A key component to this phase is developing a formal definition of what “success” means for the project implementation to be measured against. The design of physical security measures to support the proposed system are also included at this phase. Project documents are updated, refined, and a feasibility study is conducted to ensure the organization is prepared for system implementation. The final stage of this phase involves the presentation of the design to sponsors and stakeholders for review and final approval. If regulations such as HIPPA and/or PCI-DSS must be adhered to, the physical design the infrastructure components must be modeled after their specific requirements with regards to the machines data is stored on, how these machines are physically accessed, and how the data stored on these machines is disseminated to authorized parties. This is unique to the SecSDLC. While data access control is a standard consideration of any information system, HIPPA, for example, provides specific requirements in order to maintain the privacy of patient records and ensure that their data is only shared with specific authorized personnel within the medical industry. PCI-DSS covers how customer credit card details and identifiable data is stored, used, and accessed within a company’s network.
Implementation
This phase is similar to that of the SDLC. Selected solutions are purchased or developed, tested, implemented, and tested again. A penetration test could be conducted to ensure that the security measures installed perform as expected and the network resources are protected from third party intrusion. Personnel issues are revaluated, training and education programs conducted, and finally the complete package is presented to upper management for final sign off. The SDLC differs in this phase in that the system developed is rolled out to users for their daily use. The SecSDLC is implemented on the back end by network administrators, as approved by upper management. Aside from accessibility issues that are repaired during testing, the user has no involvement in this phase of the SecSDLC.
Maintenance and Change
This is the most important phase of the SecSDLC because of the evolving threat landscape. Older threats evolve and mature into more dangerous threats, and new threats aim for new attack vectors against system weaknesses. Active and constant monitoring, testing, modification, update, and repair must be conducted on information security systems in order to keep pace with maturing and emerging threats. Zero-day threats pose a significant threat to organizations at the cutting edge of their industry and their security plan must be flexible enough to be able to proactively prevent these threats while also integrating methods of recovery should an attack occur through an unknown vulnerability. This phase is the most different from the SDLC in that the SDLC framework is not designed to anticipate a software attack that requires a degree of application reconstruction. “In information security, the battle for stable, reliable systems is a defensive one” (Whitman & Mattord, 2012, p.29). The constant effort to repair damage and restore data against unseen attackers is a never ending process. Part of this phase includes the perpetual education of all personnel as new threats emerge and the security model is updated because an educated user is a powerful security tool.
Conclusion
The purpose of the SecSDLC is to provide the framework for designing and implementing a secure information system paradigm. Since it is based off the SDLC it shares many similarities in the processes and methods used to develop a comprehensive plan, but the intent and activities are different at each phase. While considering systems security is considered vital to every phase of the SDLC, the SecSDLC focuses solely on the implementation of technologies designed to protect an infrastructure from third party intrusion, data corruption, and data theft. The SDLC develops the systems used within a business, while the SecSDLC develops the system to protect these systems and an organization’s users.
ReferencesWhitman, M.E., & Mattord, H.J. (2012). Principles of Information Security (4th ed.). Retrieved from The University of Phoenix eBook Collection.
