July 10, 2025 2 Minute Read

• Learn how a risk-focused mindset, rather than striving for perfect compliance, is key to navigating the Australian Signals Directorate's (ASD) Information Security Manual (ISM) guidelines.
• Discover three crucial considerations for organizations, including those overseas, preparing for an IRAP assessment in Australia.
• Understand why clarifying early and focusing on broad ISM topics can optimize your IRAP assessment process and inform your system's security posture.

Aligning with the Australian Government’s expectations for cybersecurity can present challenges, especially for organizations unfamiliar with the frameworks in use. For those looking to work with or support government programs, understanding how systems are assessed against the Information Security Manual (ISM) is critical.

The ISM, maintained by the Australian Signals Directorate (ASD), sets out cybersecurity principles to guide the protection of government information and systems. While not a legislated standard, the ISM serves as authoritative guidance for system owners and assessors, particularly during independent security assessments performed by individuals endorsed under the Information Security Registered Assessors Program (IRAP).

IRAP assessments do not result in certification or formal accreditation. Rather, they provide risk-informed observations that help system owners, authorizing officers, and program managers understand the level of security implemented in a system, and whether it aligns with the intent of the ISM.

Below are three important tips for organizations, including those based overseas, that are preparing to undergo an IRAP assessment.

1. Start Broad Before Drilling Down

It can be tempting to begin an IRAP assessment by working directly through individual ISM controls. However, early-stage preparation is often more effective when focused on broad ISM topics and control families. This approach allows teams to:

• Identify key stakeholders or business units responsible for relevant areas (e.g., identity management, patching, logging).
• Establish whether entire ISM areas may be out of scope for the system in question (noting that justification must still be provided.)
• Accelerate the initial evidence collection process by focusing on themes, not just control IDs.

Your IRAP assessor can help confirm the assessment scope and assist in clarifying which topics or controls are most applicable to the system’s security classification and usage.

2. Focus on Risk, Not Perfection

Unlike frameworks such as SOC 2 or ISO/IEC 27001, which are often compliance- or audit-driven, an IRAP assessment is intended to support risk-informed decision-making. This means:

• Not all ISM controls will apply to every system.
• Control implementation may vary depending on the sensitivity and classification of the data handled.
• Where a control is not implemented exactly as written, assessors will consider the use of alternate controls or business justifications.

The goal of the IRAP assessment is to help inform a system’s security posture, not to achieve 100% control implementation for its own sake. System owners should focus on understanding their residual risk and addressing high-priority gaps.

3. Clarify Early, Ask Often

The ISM is extensive and subject to regular updates. Even experienced practitioners can encounter interpretative challenges, especially around technical guidelines such as system hardening, audit logging, or network segmentation.

It’s important to approach the IRAP assessment as a collaborative activity. If you’re unsure how a control should be interpreted or what kind of evidence may be required, seek clarification early. IRAP assessors are expected to be transparent about assessment expectations and are typically willing to help explain how controls apply to your specific environment.

For overseas organizations unfamiliar with the ISM, asking questions during the planning and preparation phase helps avoid rework and ensures a smoother assessment process.

Final Thought: Preparation and Partnership Are Key

IRAP assessments provide valuable insights into how well a system aligns with Australian Government cybersecurity expectations. While the process can be complex, particularly for international organizations or teams new to the ISM, these challenges can be managed through proactive preparation and collaboration with an ASD-endorsed IRAP assessor.

By adopting a risk-based mindset and engaging early with your assessor, your organization can make the most of the IRAP process and better position its systems for operating in sensitive or government-related environments.

If you are interested to see how your organization stacks up Trustwave offers IRAP Assessment Services performed by ASD-endorsed IRAP assessors. These assessments provide independent insights to help organizations understand how their systems align with the expectations set out in the ISM and PSPF, and to support system owners in identifying areas for uplift.

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