ISO/IEC 27001:2005

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ISO/IEC 27001:2005, part of the growing ISO/IEC 27000 family of standards, was an information security management system (ISMS) standard published in October 2005 by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Its full name is ISO/IEC 27001:2005 – Information technology – Security techniques – Information security management systems – Requirements. It was superseded, in 2013, by ISO/IEC 27001:2013.

ISO/IEC 27001 formally specifies a management system that is intended to bring information security under explicit management control. Being a formal specification means that it mandates specific requirements. Organizations that claim to have adopted ISO/IEC 27001 can therefore be formally audited and certified compliant with the standard (more below).

How the standard works

Most organizations have a number of information security controls. However, without an information security management system (ISMS), controls tend to be somewhat disorganized and disjointed, having been implemented often as point solutions to specific situations or simply as a matter of convention. Security controls in operation typically address certain aspects of IT or data security specifically; leaving non-IT information assets (such as paperwork and proprietary knowledge) less protected on the whole. Moreover, business continuity planning and physical security may be managed quite independently of IT or information security while Human Resources practices may make little reference to the need to define and assign information security roles and responsibilities throughout the organization.

ISO/IEC 27001 requires that management:

  • Systematically examine the organization's information security risks, taking account of the threats, vulnerabilities, and impacts;
  • Design and implement a coherent and comprehensive suite of information security controls and/or other forms of risk treatment (such as risk avoidance or risk transfer) to address those risks that are deemed unacceptable; and
  • Adopt an overarching management process to ensure that the information security controls continue to meet the organization's information security needs on an ongoing basis.

Technical security controls such as antivirus and firewalls are not normally audited in ISO/IEC 27001 certification audits: the organization is essentially presumed to have adopted all necessary information security controls since the overall ISMS is in place and is deemed adequate by satisfying the requirements of ISO/IEC 27001.

Management determines the scope of the ISMS for certification purposes and may limit it to, say, a single business unit or location. The ISO/IEC 27001 certificate does not necessarily mean the remainder of the organization, outside the scoped area, has an adequate approach to information security management.

Other standards in the ISO/IEC 27000 family of standards provide additional guidance on certain aspects of designing, implementing and operating an ISMS, for example on information security risk management (ISO/IEC 27005).

The PDCA Cycle

The PDCA cycle[1]

The 2002 version of BS 7799-2 introduced the Plan-Do-Check-Act (PDCA) cycle (Deming cycle), aligning it with quality standards such as ISO 9000. 27001:2005 applies this to all the processes in ISMS.

Plan (establishing the ISMS)
Establish the policy, the ISMS objectives, processes and procedures related to risk management and the improvement of information security to provide results in line with the global policies and objectives of the organization.
Do (implementing and workings of the ISMS)
Implement and exploit the ISMS policy, controls, processes and procedures.
Check (monitoring and review of the ISMS)
Assess and, if applicable, measure the performances of the processes against the policy, objectives and practical experience and report results to management for review.
Act (update and improvement of the ISMS)
Undertake corrective and preventive actions, on the basis of the results of the ISMS internal audit and management review, or other relevant information to continually improve the said system.

ISO 27001:2013 does not put so much emphasis on this cycle.

History of ISO/IEC 27001

BS 7799 was a standard originally published by BSI Group[2] in 1995. It was written by the United Kingdom Government's Department of Trade and Industry (DTI), and consisted of several parts.

The first part, containing the best practices for information security management, was revised in 1998; after a lengthy discussion in the worldwide standards bodies, it was eventually adopted by ISO as ISO/IEC 17799, "Information Technology - Code of practice for information security management." in 2000. ISO/IEC 17799 was then revised in June 2005 and finally incorporated in the ISO 27000 series of standards as ISO/IEC 27002 in July 2007.

The second part of BS7799 was first published by BSI in 1999, known as BS 7799 Part 2, titled "Information Security Management Systems - Specification with guidance for use." BS 7799-2 focused on how to implement an Information security management system (ISMS), referring to the information security management structure and controls identified in BS 7799-2. This later became ISO/IEC 27001:2005. BS 7799 Part 2 was adopted by ISO as ISO/IEC 27001 in November 2005.

BS 7799 Part 3 was published in 2005, covering risk analysis and management. It aligns with ISO/IEC 27001:2005.

In 2013, ISO/IEC 27001:2013 was published; it supersedes ISO/IEC 27001:2005.


An ISMS may be certified compliant with ISO/IEC 27001 by a number of Accredited Registrars worldwide. Certification against any of the recognized national variants of ISO/IEC 27001 (e.g. JIS Q 27001, the Japanese version) by an accredited certification body is functionally equivalent to certification against ISO/IEC 27001 itself.

In some countries, the bodies that verify conformity of management systems to specified standards are called "certification bodies", while in others they are commonly referred to as "registration bodies", "assessment and registration bodies", "certification/ registration bodies", and sometimes "registrars".

The ISO/IEC 27001 certification,[3] like other ISO management system certifications, usually involves a three-stage external audit process defined by the ISO/IEC 17021[4] and ISO/IEC 27006[5] standards:

  • Stage 1 is a preliminary, informal review of the ISMS, for example checking the existence and completeness of key documentation such as the organization's information security policy, Statement of Applicability (SoA) and Risk Treatment Plan (RTP). This stage serves to familiarize the auditors with the organization and vice versa.
  • Stage 2 is a more detailed and formal compliance audit, independently testing the ISMS against the requirements specified in ISO/IEC 27001. The auditors will seek evidence to confirm that the management system has been properly designed and implemented, and is in fact in operation (for example by confirming that a security committee or similar management body meets regularly to oversee the ISMS). Certification audits are usually conducted by ISO/IEC 27001 Lead Auditors. Passing this stage results in the ISMS being certified compliant with ISO/IEC 27001.
  • Ongoing involves follow-up reviews or audits to confirm that the organization remains in compliance with the standard. Certification maintenance requires periodic re-assessment audits to confirm that the ISMS continues to operate as specified and intended. These should happen at least annually but (by agreement with management) are often conducted more frequently, particularly while the ISMS is still maturing.

ISO 27001:2005 Domains

Asset Management

File:ISO27001 Asset Management.JPG
Asset Management Components

The asset register documents the assets of the company or scope in question. The asset management domain deals with analyzing and attaining the necessary level of protection of organizational assets. The typical objectives of the asset management domain is to identify and create an inventory of all assets, establish an ownership on all assets identified, establish a set of rules for the acceptable use of assets, establish a framework for classification of assets, establish an asset labeling and handling guideline. Asset management, broadly defined, refers to any system that monitors and maintains things of value to an entity or group. It may apply to both tangible assets such as buildings and to intangible concepts such as intellectual property and goodwill.

An asset is anything that has value to the organization. Assets can include infrastructure (e.g. buildings, store houses, towers etc.), physical assets ( computer equipment, communications, utility equipment, heavy machinery), software assets ( applications, software code, development tools, operational software etc.), information (database information, legal documentation, manuals, policies & procedures, organizational documents etc.), services ( transport, air conditioning, communications, utilities etc.), people (management, skills, experience etc.) and imperceptible (reputation, image etc.)also consider the asset which has been shared by the client (client related document,H/w,S/w).

Asset management is a systematic process of operating, maintaining, upgrading, and disposing of assets cost-effectively. Organizations need to identify all assets and create and maintain security controls around them. For each asset a designated owner (any team,designation) needs to be identified ( its better to avoid person name) who will be responsible for implementation of appropriate security controls. When creating an asset management policy the organization needs to define the scope of the policy (which parts of the organization are covered under the policy), responsibility (who is ultimately responsible for the policy), compliance (is compliance mandatory or not, what are the guidelines to follow), waiver criteria (on what basis can someone ask for a waiver) and effective date (from when to when is the policy applicable).

Typical policy statements for Asset Management include:

  • All assets shall be clearly identified, documented and regularly (define the periodicity) updated in an asset register
  • All assets shall have designated owners and custodians listed in the asset register
  • All assets will have the respective CIA (Confidentiality, Integrity and Availability) rating established in the asset register
  • All employees shall use company assets according to the acceptable use of assets procedures
  • All assets shall be classified according to the asset classification guideline of the company

Asset Register

Typically all business functions are required to maintain an asset register of their business units. The asset register is required to contain, at a minimum, the following information about the assets: the asset identifier, the asset name, the type and location of assets; the name of the function and process that uses this asset, the asset owner, custodian and user and the CIA (Confidentiality, Integrity, Availability) ratings of the asset. Organizations can choose to include additional information in the asset register as deemed necessary; for example, IT assets can have IP addresses as part of the asset register.

For all asset registers, a primary person responsible for the asset register needs to be identified. Typically the business unit head or director is the owner of the asset register and recognized functional heads identified are asset custodians. The asset owner is accountable for the comprehensive protection of assets owned by him/her. The asset owner may delegate the responsibility of applying the relevant controls for the maintenance of the assets to an individual/ function referred to as the ‘asset custodian’. It is the responsibility of the asset custodian to implement appropriate security controls that are required for the protection of information assets. It is the responsibility of all employees and third party staff to maintain the confidentiality, integrity and availability of the assets that they use.

Asset Classification

Assets need to be classified in order to provide an appropriate level of protection for a certain category of assets. Information assets need to be classified in terms of its value, requirements and criticality to the business operations of the company. Typical company classification guidelines follow restrictive principles.

Asset Labeling

All important and critical assets to the company shall be labeled physically / electronically as per the information labeling and handling procedures of the company. The asset owners are required to ensure that their assets are appropriately labeled (marked) for ease of identification. This may exclude information classified as ‘public’. For each classification level, the handling procedures should include the assets introduction; secure processing, storage; transmission and destruction. Classification level must be indicated wherever possible for all forms of physical / electronic information that are sensitive in nature. For example: subject of email stamped with “Confidential” etc.

Access Control

The access control domain deals with implementation of access controls across all electronic forms of information processing systems like operating systems, applications, networks or mobile platforms. Access control is the selective restriction of access to a place or other resource. Typically an organization's access control policy establishes the requirement of controls that need to be implemented for controlling access to information, information processing facilities and business processes on the basis of business and security requirements. The policy should aim to control the assimilation, authorization, and dissemination of information in a controlled manner. The typical organizational objectives of the access control policy are to establish a procedure for user registration and de-registration, establish a procedure to grant the correct level of access privilege, establish a procedure to control password use, password change and password removal, establish a procedure for managements review of access rights, establish a procedure for unattended equipment, maintain a clear desk policy, establish a procedure to control network service access, establish a control method for authentication of remote users, establish a procedure for configuration ports, establish a procedure to segregate networks, establish a procedure to use precise routing controls, establish a procedure to control system utilities and to establish a procedure to secure communications over mobile computing devices.

User Registration

A registered user is one who uses an information processing facility and provides his/her credentials, effectively proving his/her identity. Generally speaking, any person can become a registered user by providing some credentials, usually in the form of a username (or email) and password. After that, one can access information and privileges unavailable to non-registered users, usually referred to simply as guests. The action of providing the proper credentials for a system is called logging in, or signing in. Without proper policies to govern user registration, unauthorized people can gain access to confidential company information and leak it out causing harm to the organization economic status and repute. Organizations need to establish a user registration procedure which shall include controls for operating systems and applications access.

Typical policy statements can include:

  • All users shall have a unique user ID based on a standard naming convention
  • A formal authorization process shall be defined and followed for provisioning of user IDs.
  • An audit trail shall be kept of all requests to add, modify or delete user accounts/IDs
  • User accounts shall be reviewed at regular intervals
  • Employee shall sign a privilege form acknowledging their access rights
  • Access rights will be revoked for employee changes or leaving jobs
  • Privileges shall be allocated to individuals on a ‘need-to-have’ basis.
  • A record of all privilege accounts shall be maintained and updated on regular basis

Password Management

The password management deals with allocation, regulation and change of password rules of the organization. Organizations face significant security exposure in the course of routine IT operations. For example, dozens of system administrators may share passwords for privileged accounts on thousands of devices. When system administrators move on, the passwords they used during their work often remain unchanged, leaving organizations vulnerable to attack by former employees and contractors.

Weak password management means that the most sensitive passwords are often the least well defended. The need to coordinate password updates among multiple people and programs makes changing the most sensitive passwords technically difficult. Inability to secure sensitive passwords exposes organizations to a variety of security exploits. Strong, manual controls over access to privileged accounts may sometimes create unanticipated risks, such as impaired service in IT operations and escalation of physical disasters from one site to an entire organization. Inability to associate administrative actions with the people who initiated them may violate internal control requirements.

Clear Work Environment

The clear work environment can go a long way in securing the organizations security situation. Most important organizational documents are generally lying around on employee’s desks open to all individuals within the company. The main reasons for a clean desk policy are manifold including: a clean desk can produce a positive image when our customers visit the company; it reduces the threat of a security incident as confidential information will be locked away when unattended, sensitive documents left in the open can be stolen by a malicious entity.

Example of clear work environment policies include:

  • Critical information shall be protected when not required for use
  • Only authorized users shall use the photocopier machines
  • All loose documents from employee’s desks shall be confiscated at the end of business day
  • A users desktop shall not contain reference to any document directly or indirectly

Operating System & Application Control

Management of configurable security controls that are built into the operating system or application. In the scope of the ISMS framework, objective is to ensure system / application security settings are restrictive enough to protect the system (information) whilst not adversely impacting availability to the business (end user).

If an attacker can easily view someone's username and password, he can impersonate that user, and do massive damage by modifying critical information, read corporate emails, damage corporate websites etc. The procedure to log into an operating system or application control should minimize the risk of unauthorized access. The procedure shall therefore follow a strict set of rules to govern what information is displayed to the potential user during the process of log-in.

Sample operating system and application control policies include:

  • All users in the organization shall have a unique ID
  • No systems or application details shall be displayed before log-in
  • In the condition of log-in failure, the error message shall not indicate which part of the credential is incorrect
  • The number of unsuccessful log-in attempts shall be limited to 3/5/6 attempts
  • During log-in process, all password entries shall be hidden by a symbol
  • The use of system utility program shall be restricted e.g. password utility
  • All operating systems and application shall time out due to inactivity in 5/10/15/30 minutes
  • All applications shall have dedicated administrative menus to control access rights of users

Network Security

Network security assumes importance to the organization when viewed in light that networks change frequently as new users and devices are added and newer data communication technologies are introduced, usage of various networking, communications, and computing technologies to effectively meet the expanding need, sensitive data is increasingly transmitted over networks, proliferation of internet access has increased the vulnerability as employees use internet more for information and knowledge.

The primary objectives of a network security policy should be to ensure that access to company’s network is only provided to authorized users, that adequate controls are in place to manage remote users, that all equipment can be recognized uniquely, that networks should be segregated based on needs, and that appropriate network routing protocols are enabled.

Typical policy statements for Network Security include:

  • Appropriate authentication mechanisms shall be used to control the access by remote users.
  • Allocation of network access rights shall be provided as per the business and security requirements
  • Two-factor authentication shall be used for authenticating users using mobile/remote systems

See also


  1. "Taking the First Step with PDCA". 2 February 2009. Retrieved 17 March 2011.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  2. "Facts and figures".<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  3. The ISO/IEC 27001 Certification Process.
  4. ISO/IEC 17021.
  5. ISO/IEC 27006.

External links