Introduction

THE CERTIFIED INFORMATION SYSTEMS Security Professional (CISSP) certification identifies a professional who has demonstrated skills, knowledge, and abilities across a wide array of security practices and principles. The exam covers eight domains of practice, which are codified in the CISSP Common Body of Knowledge (CBK). The CBK presents topics that a CISSP can use in their daily role to identify and manage security risks to data and information systems and is built on a foundation comprising fundamental security concepts of confidentiality, integrity, availability, nonrepudiation, and authenticity (CIANA), as well as privacy and security (CIANA+PS). A variety of controls can be implemented for both data and systems, with the goal of either safeguarding or mitigating security risks to each of these foundational principles.

Global professionals take many paths into information security, and each candidate's experience must be combined with variations in practice and perspective across industries and regions due to the global reach of the certification. For most security practitioners, achieving CISSP requires study and learning new disciplines, and professionals are unlikely to work across all eight domains on a daily basis. The CISSP CBK is a baseline standard of security knowledge to help security practitioners deal with new and evolving risks, and this guide provides easy reference to aid practitioners in applying security topics and principles. This baseline must be connected with the reader's own experience and the unique operating environment of the reader's organization to be effective. The rapid pace of change in security also demands that practitioners continuously maintain their knowledge, so CISSP credential holders are also expected to maintain their knowledge via continuing education. Reference materials like this guide, along with other content sources such as industry conferences, webinars, and research are vital to maintaining this knowledge.

The domains presented in the CBK are progressive, starting with a foundation of basic security and risk management concepts in Chapter 1, "Security and Risk Management," as well as fundamental topics of identifying, valuing, and applying proper risk mitigations for asset security in Chapter 2,"Asset Security." Applying security to complex technology environments can be achieved by applying architecture and engineering concepts, which are presented in Chapter 3, "Security Architecture and Engineering." Chapter 4, "Communication and Network Security," details both the critical risks to as well as the critical defensive role played by communications networks, and Chapter 5, "Identity and Access Management," covers the crucial practices of identifying users (both human and nonhuman) and controlling their access to systems, data, and other resources. Once a security program is designed, it is vital to gather information about and assess its effectiveness, which is covered in Chapter 6, "Security Assessment and Testing," and keep the entire affair running - also known as security operations or SecOps, which is covered in Chapter 7, "Security Operations." Finally, the vital role played by software is addressed in Chapter 8, "Software Development Security," which covers both principles of securely developing software as well as risks and threats to software and development environments. The following presents overviews for each of these chapters in a little more detail.

Security and Risk Management

The foundation of the CISSP CBK is the assessment and management of risk to data and the information systems that process it. The Security and Risk Management domain introduces the foundational CIANA+PS concepts needed to build a risk management program. Using these concepts, a security practitioner can build a program for governance, risk, and compliance (GRC), which allows the organization to design a system of governance needed to implement security controls. These controls should address the risks faced by the organization as well as any necessary legal and regulatory compliance obligations.

Risk management principles must be applied throughout an organization's operations, so topics of business continuity (BC), personnel security, and supply chain risk management are also introduced in this domain. Ensuring that operations can continue in the event of a disruption supports the goal of availability, while properly designed personnel security controls require training programs and well-documented policies and other security guidance.

One critical concept is presented in this domain: the (ISC)2 code of professional ethics. All CISSP candidates must agree to be bound by the code as part of the certification process, and credential holders face penalties up to and including loss of their credentials for violating the code. Regardless of what area of security a practitioner is working in, the need to preserve the integrity of the profession by adhering to a code of ethics is critical to fostering trust in the security profession.

Asset Security

Assets are anything that an organization uses to generate value, including ideas, processes, information, and computing hardware. Classifying and categorizing assets allows organizations to prioritize limited security resources to achieve a proper balance of costs and benefits, and this domain introduces important concepts of asset valuation, classification and categorization, and asset handling to apply appropriate protection based on an asset's value. The value of an asset dictates the level of protection it requires, which is often expressed as a security baseline or compliance obligation that the asset owner must meet.

CISSP credential holders will spend a large amount of their time focused on data and information security concerns. The data lifecycle is introduced in this domain to provide distinct phases for determining data security requirements. Protection begins by defining roles and processes for handling data, and once the data is created, these processes must be followed. This includes managing data throughout creation, use, archival, and eventual destruction when no longer needed, and it focuses on data in three main states: in use, in transit, and at rest.

Handling sensitive data for many organizations will involve legal or regulatory obligations to protect specific data types, such as personally identifiable information (PII) or transactional data related to payment cards. Payment card data is regulated by the Payment Card Industry (PCI) Council, and PII often requires protections to comply with regional or local laws like the European Union General Data Protection Regulation (EU GDPR). Both compliance frameworks dictate specific protection obligations an organization must meet when collecting, handling, and using the regulated data.

Security Architecture and Engineering

The Security Architecture and Engineering domain covers topics relevant to implementing and managing security controls across a variety of systems. Secure design principles are introduced that are used to build a security program, such as secure defaults, zero trust, and privacy by design. Common security models are also covered in this domain, which provide an abstract way of viewing a system or environment and allow for identification of security requirements related to the CIANA+PS principles. Specific system types are discussed in detail to highlight the application of security controls in a variety of architectures, including client- and server-based systems, industrial control systems (ICSs), Internet of Things (IoT), and emerging system types like microservices and containerized applications.

This domain presents the foundational details of cryptography and introduces topics covering basic definitions of encryption, hashing, and various cryptographic methods, as well as attacks against cryptography known as cryptanalysis. Applications of cryptography are integrated throughout all domains where relevant, such as the use of encryption in secure network protocols, which is covered in Chapter 4. Physical architecture security - including fire suppression and detection, secure facility design, and environmental control - is also introduced in this domain.

Communication and Network Security

One major value of modern information systems lies in their ability to share and exchange data, so fundamentals of networking are presented in the Communication and Network Security domain along with details of implementing adequate security protections for these communications. This domain introduces common models used for network services, including the Open Systems Interconnection (OSI) and Transmission Control Protocol/Internet Protocol (TCP/IP) models. These layered abstractions provide a method for identifying specific security risks and control capabilities to safeguard data, and the domain presents fundamentals, risks, and countermeasures available at each level of the OSI and TCP/IP models.

Properly securing networks and communications requires strategic planning to ensure proper architectural choices are made and implemented. Concepts of secure network design - such as planning and segmentation, availability of hardware, and network access control (NAC) - are introduced in this domain. Common network types and their specific security risks are introduced as well, including software-defined networks...