(ISC)2 CISSP Certified Information Systems Security Professional Official Study Guide. Mike Chapple
has six phases: Categorize, Select, Implement, Assess, Authorize, and Monitor.
NIST Cybersecurity Framework (CSF) (www.nist.gov/cyberframework) is designed for critical infrastructure and commercial organizations, and consists of five functions: Identify, Protect, Detect, Respond, and Recover. It is a prescription of operational activities that are to be performed on an ongoing basis for the support and improvement of security over time.
International Organization for Standardization (ISO)/ International Electrotechnical Commission (IEC) 27000 family group (www.itgovernanceusa.com/iso27000-family) is an international standard that can be the basis of implementing organizational security and related management practices.
Information Technology Infrastructure Library (ITIL) (itlibrary.org), initially crafted by the British government, is a set of recommended best practices for optimization of IT services to support business growth, transformation, and change. ITIL focuses on understanding how IT and security need to be integrated with and aligned to the objectives of an organization. ITIL and operational processes and is often used as a starting point for the crafting of a customized IT security solution within an established infrastructure.
Due Diligence and Due Care
Why is planning to plan security so important? One reason is the requirement for due diligence and due care. Due diligence is establishing a plan, policy, and process to protect the interests of an organization. Due care is practicing the individual activities that maintain the due diligence effort. For example, due diligence is developing a formalized security structure containing a security policy, standards, baselines, guidelines, and procedures. Due care is the continued application of this security structure onto the IT infrastructure of an organization. Operational security is the ongoing maintenance of continued due diligence and due care by all responsible parties within an organization. Due diligence is knowing what should be done and planning for it; due care is doing the right action at the right time.
In today's business environment, prudence is mandatory. Showing due diligence and due care is the only way to disprove negligence in an occurrence of loss. Senior management must show due care and due diligence to reduce their culpability and liability when a loss occurs.
Security Policy, Standards, Procedures, and Guidelines
For most organizations, maintaining security is an essential part of ongoing business. To reduce the likelihood of a security failure, the process of implementing security has been formalized with a hierarchical organization of documentation. Developing and implementing documented security policy, standards, procedures, and guidelines produces a solid and reliable security infrastructure.
Security Policies
The top tier of the formalization is known as a security policy. A security policy is a document that defines the scope of security needed by the organization and discusses the assets that require protection and the extent to which security solutions should go to provide the necessary protection. The security policy is an overview or generalization of an organization's security needs. It defines the strategic security objectives, vision, and goals and outlines the security framework of an organization. The security policy is used to assign responsibilities, define roles, specify audit requirements, outline enforcement processes, indicate compliance requirements, and define acceptable risk levels. This document is often used as the proof that senior management has exercised due diligence in protecting itself against intrusion, attack, and disaster. Security policies are compulsory.
Many organizations employ several types of security policies to define or outline their overall security strategy. An organizational security policy focuses on issues relevant to every aspect of an organization. An issue-specific security policy focuses on a specific network service, department, function, or other aspect that is distinct from the organization as a whole. A system-specific security policy focuses on individual systems or types of systems and prescribes approved hardware and software, outlines methods for locking down a system, and even mandates firewall or other specific security controls.
From the security policies flow many other documents or sub-elements necessary for a complete security solution. Policies are broad overviews, whereas standards, baselines, guidelines, and procedures include more specific, detailed information on the actual security solution. Standards are the next level below security policies.
Acceptable Use Policy
An acceptable use policy (AUP) is a commonly produced document that exists as part of the overall security documentation infrastructure. This policy defines a level of acceptable performance and expectation of behavior and activity. Failure to comply with the policy may result in job action warnings, penalties, or termination.
Security Standards, Baselines, and Guidelines
Once the main security policies are set, then the remaining security documentation can be crafted under the guidance of those policies. Standards define compulsory requirements for the homogenous use of hardware, software, technology, and security controls. They provide a course of action by which technology and procedures are uniformly implemented throughout an organization.
A baseline defines a minimum level of security that every system throughout the organization must meet. A baseline is a more operationally focused form of a standard. All systems not complying with the baseline should be taken out of production until they can be brought up to the baseline. The baseline establishes a common foundational secure state on which all additional and more stringent security measures can be built. Baselines are usually system specific and often refer to an industry or government standard.
Guidelines are the next element of the formalized security policy structure. A guideline offers recommendations on how standards and baselines are implemented and serves as an operational guide for both security professionals and users. Guidelines are flexible, so they can be customized for each unique system or condition and can be used in the creation of new procedures. They state which security mechanisms should be deployed instead of prescribing a specific product or control and detailing configuration settings. They outline methodologies, include suggested actions, and are not compulsory.
Security Procedures
Procedures are the final element of the formalized security policy structure. A procedure or standard operating procedure (SOP) is a detailed, step-by-step how-to document that describes the exact actions necessary to implement a specific security mechanism, control, or solution. A procedure could discuss the entire system deployment operation or focus on a single product or aspect. They must be updated as the hardware and software of a system evolve. The purpose of a procedure is to ensure the integrity of business processes through standardization and consistency of results.
At the top of the formalization security policy documentation structure there are fewer documents because they contain general broad discussions of overview and goals. There are more documents further down the formalization structure (in other words, guidelines and procedures) because they contain details specific to a limited number of systems, networks, divisions, and areas.
Keeping these documents as separate entities provides these benefits:
Not all users need to know the security standards, baselines, guidelines, and procedures for all security classification levels.
When changes occur, it is easier to update and redistribute only the affected material rather than updating a monolithic policy and redistributing it throughout the organization.
Many organizations struggle just to define the foundational parameters of their security, much less detail every single aspect