Separation of duties is a key concept of internal controls and is the most difficult and sometimes the most costly one to achieve. This objective is achieved by disseminating the tasks and associated privileges for a specific security process among multiple people.
The term SoD is already well-known in financial accounting systems. Companies in all sizes understand not to combine roles such as receiving checks (payment on account) and approving write-offs, depositing cash and reconciling bank statements, approving time cards and have custody of pay checks, etc. However, SoD is fairly new to the IT organization. It is not a surprise that concerns are being raised about separation of duties in IT given that a very high portion of SOX internal control issues come from or rely on IT. Separation of duties is a fundamental principles of many regulatory mandates such as Sarbanes-Oxley (SOX), the Gramm-Leach-Bliley Act (GLBA) and others. As a result IT organizations must now place greater emphasis on separation of duties across all IT functions, especially security.
Security Separation of Duties
Separation of duty, as it relates to security, has two primary objectives. The first is the prevention of conflict of interest, the appearance of conflict of interest, wrongful acts, fraud, abuse and errors. The second is the detection of control failures that include security breaches, information theft, and circumvention of security controls. Security controls are measures taken to safeguard an information system from attacks against the confidentiality, integrity, and availability of computer systems, networks and the data they use. In addition, the security controls are selected and applied based on a risk assessment of the information system. These controls restrict the amount of power / influence held by any one individual. Proper separation of duties, of course, is designed to ensure that individuals don't have conflicting responsibilities or is responsible for reporting on themselves or their superior.
There is an easy test for Separation of Duties. First ask if any one person alter or destroy your financial data without being detected. For the second test ask is any one person can steal or exfiltrate sensitive information. The final test asks if any one person has influence over controls design, implementation and reporting of the effectiveness of the controls. If the answer to any of these questions is YES, then you need to take a hard look at the separation of duties.
Now, as this relates specifically to security, the individual responsible for designing and implement security cannot be the same person as the person responsible for testing security, conducting security audits as well as monitoring and reporting on security. For these reasons, the reporting relationship of the individual responsible for information security should not be to the Chief Information Officer as is traditionally the case.