Comprehensive and Detailed Explanation (250–350 words)
Exact alignment with EC-Council CCISO documentation and referenced ISO standards
According to EC-Council Chief Information Security Officer (CCISO) program documentation, measuring the effectiveness of an Information Security Management System (ISMS) requires defined, repeatable, and standardized metrics. The CCISO body of knowledge explicitly aligns ISMS performance measurement with ISO/IEC 27004, which is the international standard dedicated to information security metrics, measurement, and reporting.
ISO/IEC 27004 provides guidance on how organizations should develop, implement, analyze, and improve measurements that assess the effectiveness and efficiency of an ISMS. The CCISO program emphasizes that governance-level leaders must rely on quantifiable, objective metrics rather than operational frameworks or risk assessment standards when evaluating ISMS performance. ISO 27004 directly supports this executive requirement by defining what to measure, how to measure it, and how to interpret results in the context of business objectives.
In contrast, ITIL is a service management framework focused on IT service delivery and lifecycle management, not on measuring ISMS effectiveness. While ITIL supports operational excellence, CCISO materials clearly distinguish IT service management from security governance measurement.
COBIT (corrected from the incorrect spelling “CODIT”) is a governance and management framework for enterprise IT. Although COBIT includes security-related control objectives and maturity models, it is not designed specifically to measure ISMS effectiveness at the level required by ISO-aligned security programs.
ISO/IEC 27005, meanwhile, focuses on information security risk management. The CCISO curriculum explains that risk assessment is a critical component of an ISMS, but it does not provide guidance on performance measurement or effectiveness metrics.
Therefore, as confirmed in EC-Council CCISO documentation and its reliance on ISO standards, ISO/IEC 27004 is the correct and authoritative standard used to measure the effectiveness of an ISMS, making Option C the correct answer.