Ways to Strengthen Cyber Response Capabilities, Based on Incident Response

This article is not intended to provide legal advice; please be sure to verify accurate information with a lawyer or the relevant government agency.

In October 2026, the “ Cyber Response Capabilities Enhancement Act ” and its implementing legislation will take effect.
While media coverage tends to focus on “proactive cyber defense,” the government’s use of communications data, and measures to neutralize attack servers, the aspects that will actually have the greatest practical impact on corporate security professionals are, in fact, the more mundane details. Specifically, these are the obligation to report incidents to the government — starting with the “detection” of an incident— and the mechanisms supporting this, such as asset registration and public-private information sharing.

Rather than providing a clause-by-clause analysis of the law, this article organizes the information from the perspective of “What does this law require when viewed from the front lines of incident response?” To put it simply, what this law is really asking is not whether you have the ability to write a report , but whether you have a system in place to create incident records of sufficient quality to withstand scrutiny—and to do so simultaneously with the response itself.

1. First, the minimum required background knowledge

The Cyber Response Capability Enhancement Act (official title: Act on the Prevention of Damage Caused by Unlawful Acts Against Critical Computers) was enacted on May 16, 2025, promulgated on May 23 of the same year, and its main provisions will take effect on October 1, 2026. The Act has four main pillars.
ref: Bill Information for the 217th Session of the Diet (Regular Session) - Bill on the Prevention of Damage Caused by Unlawful Acts Against Important Computers

1. Strengthening Public-Private Partnerships (Asset Registration, Incident Reporting, Public-Private Consultative Council)

2. Use of Communication Data (Collection and Analysis of Communication Data for Attack Detection)

3. Access and Mitigation Measures (Police and Self-Defense Forces’ Response to Attack Infrastructure)

4. Establishment of Organizational Structures and Systems (National Cyber Coordination Office, Cyber Communications and Information Oversight Commission, etc.)

Of these, the only part that imposes direct obligations on companies is Part 1, which concerns public-private partnerships. The entities directly subject to these obligations are the “Special Social Infrastructure Operators” (commonly referred to as critical infrastructure operators)—approximately 257 companies across 15 industries—that are linked to the critical infrastructure system under the Economic Security Promotion Act. These include the electricity, gas, water, telecommunications, finance, aviation, and railway sectors.

If you’re thinking, “This doesn’t apply to us because we’re not one of the 257 companies,” please keep reading just a little longer. When you look at how the obligations are structured, you’ll see that their scope extends far beyond the definition of reportable equipment and into the supply chain.

2. Applying the Law to the Incident Response Lifecycle

Let’s overlay the requirements of this law onto the standard incident response lifecycle (preparation → detection and analysis → containment, eradication, and recovery → post-incident review). Doing so reveals that this law is, in essence, “a law that adds the government as a stakeholder to each phase of the incident response process.”

Preparation Phase: Asset Management Becomes a Legal Obligation

When introducing or modifying a “specified critical computer,” the affected business operator is required to report the product name, model number, and other relevant details to the minister with jurisdiction over the business.

As a practitioner in incident response, it is important to pay close attention to the definition of “specified critical computers.” This definition encompasses not only the systems that handle core business operations but also “devices that could cause the specified critical facilities to cease functioning or experience a decline in performance in the event of a cyberattack”; examples include firewalls, VPN devices, authentication servers, devices within the DMZ, and access control devices.

In recent years, the initial points of entry for major incidents have been vulnerabilities in VPN equipment and authentication infrastructure. In other words, this reporting system is designed to enable the government to identify the assets that attackers target first; conversely, this means that companies cannot fulfill their reporting obligations unless they maintain a registry of “assets that could serve as points of entry” on a regular basis.

In the world of incident response, it has long been said that “the quality of incident response is determined during the preparation phase” and that “organizations that do not understand their own assets cannot determine the scope of a breach.” This law can be interpreted as translating those lessons into legal obligations.

Detection and Analysis Phase: The reporting clock starts ticking from the moment of “awareness”

The most important aspect of the incident reporting obligation under this Act (Article 5) in terms of practical incident response is that the trigger for reporting is “upon becoming aware of the occurrence of a specified infringement event.” It is not when the damage has been confirmed, nor when the investigation has been completed.

Furthermore, the reporting requirement is not limited to incidents that resulted in actual harm.
If you become aware of an “incident that could have caused such harm”—commonly known as a near miss — you are also required to report it.

This has significant implications for incident response operations.

• The triage decision itself—whether “this is an incident or merely an alert”—determines when a legal obligation arises.

• Unless you keep a record of “when, who, and what was acknowledged,” you will not be able to demonstrate later that you have properly fulfilled your reporting obligations.

• Unless we clarify the relationship between escalation criteria from SOC and MDR vendors and the legal definition of “awareness,” the risk of missed or delayed reporting will fall on the outsourcing provider.

While many organizations’ incident response playbooks are triggered by a “declaration of a major incident,” under this law, evidence is required starting from the triage phase—even before such a declaration is made.

Containment and Recovery Phase: The Government May Take the Lead in the Response

The Maintenance Act contains provisions allowing the government to take access and mitigation measures to prevent serious harm. It has been pointed out that if a business partner’s system of a critical infrastructure operator is used as a springboard for an attack, that business partner’s system may also be subject to such measures.

Furthermore, violations of reporting obligations or inappropriate responses may result in a corrective order from the competent minister; failure to comply may result in a fine (up to 2 million yen for violations of reporting obligations). While the fine itself is not substantial, the real practical risk lies not in the fine, but rather in the loss of trust from business partners due to the fact that a corrective order was issued, as well as the need to manage interactions with regulatory authorities concurrently while responding to the incident.It is necessary to explicitly incorporate the role of “dealing with regulatory authorities” into the incident response chain of command (incident commander system).

Post-Activity Phase: Reporting and Information Sharing Require the Externalization of “Learning”

Traditionally, post-incident reviews (post-mortems) were internal activities aimed at preventing recurrence. Under this law, information is aggregated by the government through incident reports, analyzed by the National Cyber Security Coordination Office, and used to issue warnings to other operators. Furthermore, in the fall of 2026, a new public-private council—comprising critical infrastructure operators, security vendors, government agencies, and others—is scheduled to be established, and the mutual sharing of threat intelligence during both normal and emergency situations is set to begin.

In other words, structuring and preserving the technical insights gained from a company’s own incidents—such as attack techniques and IoCs— in a format and level of detail that allows for sharing is evolving from a mere best practice into an institutional prerequisite.

3. What Will Happen to Reporting Procedures: Standardized Forms and a Single Point of Contact

I can almost hear people groaning, “Are we going to have to report to yet another department?” but there’s some good news here, too.

　Currently, the reporting and consultation requirements that Japanese companies must fulfill in the event of an incident are scattered across multiple systems, including reports to the Personal Information Protection Commission under the Act on the Protection of Personal Information, incident reports to the relevant government ministries and agencies under various industry laws, and notifications to and consultations with the police. Since the reporting obligations under the Enhanced Act will be added to these, the government is working to establish a system to handle them in a centralized manner.

• Phase 1 (October 2025–): Implementation of a standardized reporting format for DDoS attacks and ransomware incidents ( National Cyber Security Office, “Standardization of Incident Reporting Formats for Damage Caused by Cyberattacks” )

• Phase 2 (in conjunction with the enforcement of reporting obligations under the Enhanced Act): Establish a reporting reception system and centralize the point of contact. The plan is to enable users to submit reports to the relevant ministries and the Personal Information Protection Commission, as well as consult with the police, all through a single system.

From a practical incident response perspective, this means that “reports” are shifting from free-form documents toward structured data with defined fields. The standardized format includes items such as an overview of the incident, a chronology of events, the types and number of affected devices, system operational status, information on attack techniques, and the status of public disclosure.

All of this information naturally arises during the incident response process. If you have established a process for systematically documenting the response timeline, affected assets, and detected attack methods, creating the report is simply a matter of “copying and pasting.” Conversely, piecing together a report by the deadline from information scattered across Slack threads and personal notes is the task that consumes the most response resources.

4. Learning from the EU’s Lead to Predict What Comes Next

It becomes easier to predict the future direction of this Japanese system if we consider it within the context of international trends. A useful point of reference is the EU’s NIS 2 Directive.

NIS2 requires operators across a wide range of sectors, including critical infrastructure, to follow a multi-stage, time-bound reporting process for serious incidents: early warning within 24 hours → incident notification within 72 hours (including an initial assessment of severity and impact, and IoCs if possible) → final report within one month.Fines for violations can reach up to 10 million euros or 2% of global revenue—a level comparable to that of the GDPR. The U.S. CIRCIA also sets deadlines of 72 hours for serious incidents and 24 hours for ransomware attacks, and the “awareness-based, time-limited, multi-stage” reporting model is converging across Japan, the U.S., and Europe.
*Reference: PwC, European Cybersecurity Laws, What Is the NIS 2 Directive?

As it stands, Japan’s current強化法 does not explicitly stipulate multi-stage reporting with time-sensitive deadlines as strict as those in NIS2. However, it is worth noting that a provision for a review after three years was added during the legislative deliberation process.(*Reference: Nikkei X TECH—Bill on Proactive Cyber Defense Passes Lower House; Amendments Added to Strengthen Reporting to the Diet and Include a Review After Three Years )
Given that the EU significantly expanded the scope of covered sectors and tightened reporting deadlines when amending the NIS Directive to NIS2, the following developments are considered realistic scenarios for Japan at the time of its review.

• Expansion of Target Industries and Businesses (from the current 257 companies to a broader range of “key businesses”)

• Clarification of Reporting Deadlines and Stages (Alignment with the NIS2-style 24-hour/72-hour/1-month model)

• The Ripple Effect of Reporting Obligations on the Supply Chain (Contractors and Vendors)—At this point, the reporting obligations in the event that a business partner is attacked have not been clearly defined, and this “gray area” itself can be interpreted as a sign of future regulatory expansion.

The requirements currently imposed on core infrastructure operators are likely to extend to a wider range of companies in a few years. This is why even companies not directly subject to this law cannot afford to treat it as “someone else’s problem.”

5. What We Should Start Preparing for Now in Terms of Incident Response Capabilities

Based on the above, we have narrowed down the preparations needed from an incident response perspective to five key points.

(1) Linking the Asset Register and Incident Records
Conduct an inventory and register equipment that may qualify as “specified critical computers” (perimeter devices, authentication infrastructure, access control). This ensures that, when an incident occurs, it is possible to immediately identify “which registered assets were affected.” This is because the registration and incident reporting systems are integrated and refer to the same register.

(2) Document the definition of “awareness” and triage criteria
Determine which alerts and which escalations constitute “awareness.” Align the relationship between escalation criteria and reporting obligations with third-party service providers (such as SOCs and MDR providers) at both the contractual and operational levels.

(3) Implement a process that preserves the timeline as a byproduct of the response
Record the time of detection, the time of awareness, each decision made, and the measures taken in chronological order. Rather than increasing the workload just for the sake of reporting, establish a system (tools and templates) where the response record itself serves as the basis for the report. NIS2 specifically states that “resources for incident response must not be diverted to fulfill reporting obligations” precisely because this tends to happen.

(4) Incorporate reports to regulatory authorities into the incident command structure
Who finalizes the report text, and who communicates with the relevant government agencies? Clearly define the role of “regulatory authority response” within the escalation path, which includes public relations, legal, and senior management. Include the reporting process in training (tabletop exercise) scenarios.

(5) Design reporting workflows with contractors and group companies
If your company is a core infrastructure provider, include in the contract the obligation and deadlines for incident reporting by system operation contractors. If your company is a vendor, establish a system that allows you to provide the information necessary to support your customers’ reporting obligations (such as affected devices and attack techniques) within the specified deadlines.

In Conclusion: This Law Is a “Law on Records”

Although the Cyber Response Capability Enhancement Act is marketed under the flashy banner of “proactive cyber defense,” from the perspective of corporate practice, it is essentially a law that calls for greater transparency and a more structured approach to incident response.

What assets do you have (notification)? When and what did you become aware of (reporting trigger)? How did you respond, and what did you learn (reporting and information sharing)? The one common thread running through all of these is “responding while maintaining verifiable records.”

Moreover, this is something that excellent incident response teams have been doing for a long time, even without a law in place. The law’s enforcement in October 2026 will mark a turning point where the difference between organizations that have such discipline and those that do not will become visible from the outside in the form of regulatory compliance.

References (Primary Information and Major Sources)

• Cabinet Secretariat: “Regarding the Act on Strengthening Cyber Response Capabilities and the Act on the Establishment of Related Systems” (National Cyber Security Office)

• Cybersecurity Strategy (Approved by the Cabinet on December 23, Reiwa 7)

• Mori Hamada & Matsumoto Law Firm: “Efforts Toward Centralized Reporting of Security Incidents”

• Nikkei CrossTech: “Cyber Response Capability Enhancement Act to Take Effect in October; Risk of Being Excluded by Business Partners Also Exists”

• PwC: “The Impact of Proactive Cyber Defense on Critical Infrastructure Operators (Part 1)”

• PwC “ The Impact of Proactive Cyber Defense Implementation on Critical Infrastructure Operators (Part 2) ”

• EU NIS 2 Directive (Directive (EU) 2022/2555)