What is a “Separation of Duties”?

Often, I find in my job as a security professional that I must explain what a separation of duties is and why it is necessary in an organization. The term “separation of duties” seems a little nebulous for many but it is the act of separating a business process into several distinct parts. These distinct parts of a business process that are normally separated are the execution, approval and audit functions of the process.

Examples of Separation of Duties:

1. Security incident investigation – Typically, an investigation is initiated by a security operations function (CSIRT) and then after an investigation is completed the assessment of the incident response process is performed by IT Audit or an Internal Audit department to ensure the process is being executed based on the documented procedure.

2. Payroll – Typically, payroll departments are responsible for the distribution of checks, the manager of the employee being paid approves the hours worked and then an Internal Audit function may check to ensure all the processes are being followed and the appropriate payment amounts are being completed.

3. Vulnerability Management – Security operations or engineering functions typically use a scanning application such as a Rapid7, McAfee Vulnerability Manager or QualysGuard scanning engine to scan devices on the network for security vulnerabilities, once a scan is completed tickets may be created to address these vulnerabilities. An IT Audit department may come in and request a “sample” of the tickets to ensure that proper remediation is being performed and that tickets are not being closed without an actual remediation of the vulnerabilities.

The Goal:

The primary goal for implementing proper separation of duties should always be the prevention of fraud. By separating business processes into these segments, we can ensure that a business process is efficiently executed and checked by an independent party that can assure the execution is appropriately. Implementation of a separation of duties prevents a single business process to be completely managed by a single individual and thus requires collusion to occur before fraud can take place. In most cases, it is more difficult (however not impossible) to enlist the help of others to perform fraud. The primary goal is to reduce the risk of fraud, not to completely prevent it.