- Dec 20, 2002
- Defining Security Principles
- Security Management Planning
- Risk Management and Analysis
- Policies, Standards, Guidelines, and Procedures
- Examining Roles and Responsibility
- Management Responsibility
- Understanding Protection Mechanisms
- Classifying Data
- Employment Policies and Practices
- Managing Change Control
- Security Awareness Training
Policies, Standards, Guidelines, and Procedures
Know how to set policies and how to derive standards, guidelines, and implement procedures to meet policy goals.
Part of information security management is determining how security will be maintained in the organization. Management defines information security policies to describe how the organization wants to protect its information assets. After policies are outlined, standards are defined to set the mandatory rules that will be used to implement the policies. Some policies can have multiple guidelines, which are recommendations as to how the policies can be implemented. Finally, information security management, administrators, and engineers create procedures from the standards and guidelines that follow the policies. Figure 3.4 shows the relationships between these processes. The rest of this section discusses how to create these processes.
Figure 3.4 The relationships of the security processes.
Information Security Policies
Information security policies are high-level plans that describe the goals of the procedures. Policies are not guidelines or standards, nor are they procedures or controls. Policies describe security in general terms, not specifics. They provide the blueprints for an overall security program just as a specification defines your next product.
Questions always arise when people are told that procedures are not part of policies. Procedures are implementation details; a policy is a statement of the goals to be achieved by procedures. General terms are used to describe security policies so that the policy does not get in the way of the implementation. For example, if the policy specifies a single vendor's solution for a single sign-on, it will limit the company's ability to use an upgrade or a new product. Although your policy documents might require the documentation of your implementation, these implementation notes should not be part of your policy.
Information security policies are the blueprints, or specifications, for a security program.
Although policies do not discuss how to implement information security, properly defining what is being protected ensures that proper control is implemented. Policies tell you what is being protected and what restrictions should be put on those controls. Although product selection and development cycles are not discussed, policies should help guide you in product selection and best practices during deployment. Implementing these guidelines should lead to a more secure environment.
How Policies Should Be Developed
Before policy documents can be written, the overall goal of the policies must be determined. Is the goal to protect the company and its interactions with its customers? Or will you protect the flow of data for the system? In any case, the first step is to determine what is being protected and why it is being protected.
Policies can be written to affect hardware, software, access, people, connections, networks, telecommunications, enforcement, and so on. Before you begin the writing process, determine which systems and processes are important to your company's mission. This will help you determine what and how many policies are necessary to complete your mission. After all, the goal here is to ensure that you consider all the possible areas in which a policy will be required.
Define What Policies Need to Be Written
Information security policies do not have to be a single document. To make it easier, policies can be made up of many documentsjust like the organization of this book (rather than streams of statements, it is divided into chapters of relevant topics). So, rather than trying to write one policy document, write individual documents and call them chapters of your information security policy. By doing so, they are easier to understand, easier to distribute, and easier to provide individual training with because each policy has its own section. Smaller sections are also easier to modify and update.
How many policies should you write? I hate to answer a question with a question, but how many areas can you identify in your scope and objectives? For each system within your business scope and each subsystem within your objectives, you should define one policy document. It is okay to have a policy for email that is separate from one for Internet usage. It is not a problem to have a policy for antivirus protection and a separate policy for Internet usage. A common mistake is trying to write a policy as a single document using an outline format. Unfortunately, the result is a long, unmanageable document that might never be read, let alone gain anyone's support. Table 3.3 has a small list of the policies your organization can have.
Table 3.3 SAMPLE LIST OF POTENTIAL POLICIES
User and Physical Policies
Access Control Policies
External Access Policies
Authentication and Access Controls Encryption
Public Key Infrastructures
Web and Internet Email
Identify What Is to Be Protected
If you remember that computers are the tools for processing the company's intellectual property, that the disks are for storing that property, and that the networks are for allowing that information to flow through the various business processes, you are well on your way to writing coherent, enforceable security policies.
The following is an example of what can be inventoried:
Human resource assets
It is important to have a complete inventory of the information assets supporting the business processes. The best way to create this list is to perform a risk assessment inventory. However, other methods, such as using purchase information, are available Regardless of the methods used, you should ensure that everything is documented. Inventories, like policies, must go beyond the hardware and software. There should be a list of documentation on programs, hardware, systems, local administrative processes, and other documentation that describes any aspect of the technical business process. These documents can contain information regarding how the business works and can show areas that can be attacked. Remember, the business processes can be affected by industrial espionage as well as hackers and disgruntled employees.
Similarly, the inventory should include all preprinted forms, paper with the organization's letterhead, and other material with the organization's name used in an "official" manner. Using blank invoices and letterhead paper allows someone to impersonate a company official and use the information to steal money or even discredit the organization. So, include those supplies in the inventory so policies can be written to protect them as assets.
The most important and expensive of all resources are the human resources who operate and maintain the items inventoried. Performing an inventory of the people involved with the operations and use of the systems, data, and noncomputer resources provides insight into which policies are necessary.
Creating an inventory of people can be as simple as creating a typical organizational chart of the company. This can be cumbersome, however, if you are including a thousand, or even a few hundred, people in one document. Moreover, organizational charts are notoriously rigid and do not assume change or growth. The inventory, then, could include the type of job performed by a department, along with the level of those employees' access to the enterprise's data.
Identify from Whom It Is Being Protected
Defining access is an exercise in understanding how each system and network component is accessed. Your network might have a system to support network-based authentication and another supporting intranet-like services, but are all the systems accessed like this? How is data accessed amongst systems? By understanding how information resources are accessed, you should be able to identify on whom your policies should concentrate. Some considerations for data access are
Authorized and unauthorized access to resources and information
Unintended or unauthorized disclosure of information
Bugs and user errors
Primarily, the focus should be on who can access resources and under what conditions. This is the type of information that can be provided during a risk analysis of the assets. The risk analysis then determines which considerations are possible for each asset. From that list, policies can then be written to justify their use.
When creating policies for an established organization, there is an existing process for maintaining the security of the assets. These policies are used as drivers for the policies. For other policies in which there are no technology drivers, standards can be used to establish the analysts' mandatory mechanisms for implementing the policy.
Regardless of how the standards are established, by setting standards, policies that are difficult to implement or that affect the entire organization are guaranteed to work in your environment. Even for small organizations, if the access policies require one-time-use passwords, the standard for using a particular token device can make interoperability a relative certainty.
Baselines are used to create a minimum level of security necessary to meet policy requirements. Baselines can be configurations, architectures, or procedures that might or might not reflect the business process but that can be adapted to meet those requirements. You can use these baselines as an abstraction to develop standards.
Most baselines are specific to the system or configuration they represent, such as a configuration that allows only Web services through a firewall. However, like most baselines, this represents a minimum standard that can be changed if the business process requires it. One example is to change the configuration to allow a VPN client to access network resources.
Standards and baselines describe specific products, configurations, or other mechanisms to secure the systems. Sometimes security cannot be described as a standard or set as a baseline, but some guidance is necessary. These are areas where recommendations are created as guidelines to the user community as a reference to proper security. For example, your policy might require a risk analysis every year. Rather than require specific procedures to perform this audit, a guideline can specify the methodology that is to be used, leaving the audit team to work with management to fill in the details.
Setting and Implementing Procedures
The last step before implementation is creating the procedures. Procedures describe exactly how to use the standards and guide- lines to implement the countermeasures that support the policy. These procedures can be used to describe everything from the configuration of operating systems, databases, and network hardware to how to add new users, systems, and software. As was illustrated in Figure 3.4, procedures should be the last part of creating an information security program.
Procedures are written to support the implementation of the policies. Because policies change between organizations, defining which procedures must be written is impossible. For example, if your organization does not perform software development, procedures for testing and quality assurance are unnecessary. However, some types of procedures might be common amongst networked systems, including
AuditingThese procedures can include what to audit, how to maintain audit logs, and the goals of what is being audited.
AdministrativeThese procedures can be used to have a separation of duties among the people charged with operating and monitoring the systems. These procedures are where you can show that database administrators should not be watching the firewall logs.
Access controlThese procedures are an extension of administrative procedures that tell administrators how to configure authentication and other access control features of the various components.
ConfigurationThese procedures cover the firewalls, routers, switches, and operating systems.
Incident responseThese procedures cover everything from detection to how to respond to the incident. These procedures should discuss how to involve management in the response as well as when to involve law enforcement.
Physical and environmentalThese procedures cover not only the air conditioning and other environmental controls in rooms where servers and other equipment are stored, but also the shielding of Ethernet cables to prevent them from being tapped.
Implementation of these procedures is the process of showing due diligence in maintaining the principles of the policy. Showing due diligence is important to demonstrate commitment to the policies, especially when enforcement can lead to legal proceedings. Demonstrating commitment also shows management support for the policies. When management does not show this type of commitment, the users tend to look upon the policies as unimportant. When this happens, a disaster will eventually follow.
When enforcing the policies can lead to legal proceedings, an air of noncompliance with the policies can be used against your organization as a pattern showing selective enforcement and can question accountability. This can destroy the credibility of a case or a defense that can be far reachingit can affect the credibility of your organization as well.
Showing due diligence can have a pervasive effect. Management supporting the administrators showing the commitment to the policies leads to the users taking information security seriously. When everyone is involved, the security posture of your organization is more secure. This does require the users to be trained in the policies and procedures, however. Therefore, training is part of the overall due diligence of maintaining the policies and should never be overlooked. To be successful, resources must be assigned to maintain a regular training program.