Correct Answer:

See The answer in Explanation part below.
Explanation:
Step 1 - Recognise the shared-facility authorisation problem. The data centre facility itself, and the general access points, common areas, and physical security controls governing entry to the building, are owned and operated by the data centre operator - a separate legal entity - not by Silverpeak. Silverpeak's authorisation can validly cover its own locked cage and the equipment within it, but it cannot validly authorise a physical intrusion attempt against the building's general access controls, which are the data centre operator's own infrastructure and responsibility, exactly analogous to the cloud/SaaS/telecommunications-provider authorisation-boundary issue addressed elsewhere in this syllabus, now applied to a physical rather than purely technical context.
Step 2 - Recognise the additional multi-tenant risk dimension. Beyond the pure authorisation question, a physical intrusion attempt against the shared facility risks affecting or alarming the other two unrelated Authorized Institutions whose cages are in immediate physical proximity - for example, if the attempt triggers a wider facility security response, lockdown, or law enforcement involvement affecting the whole building, not just Silverpeak's area. This mirrors the "shared multi-tenant environment" risk principle covered elsewhere in this syllabus regarding cloud infrastructure, now applied physically, and materially raises the stakes of proceeding without the operator's explicit involvement.
Step 3 - Do not proceed with the physical facility-entry component as currently framed. Given Steps 1 and
2, this specific element should not proceed on the basis of Silverpeak's authorisation alone. The professionally correct response to the Control Group is to explain clearly why their own authorisation cannot legally or safely extend to testing the shared building's general access controls, however enthusiastic they are about a comprehensive test.
Step 4 - Identify legitimate alternative approaches. Rather than simply declining outright, you should discuss constructive alternatives with the Control Group: (i) engaging the data centre operator directly to seek their explicit, separate consent for a properly scoped and coordinated physical test of the building's general access controls (which, if obtained, would need to be documented and would still require care given the other tenants' interests, potentially requiring their awareness or at least the operator's confirmation that testing is compatible with its own obligations to other tenants); (ii) narrowing the physical testing component to elements genuinely within Silverpeak's own control, such as testing access controls on Silverpeak's own locked cage itself (e.g., attempting to gain entry to the cage assuming a tester has already reached the general shared area through legitimate means, or testing whether Silverpeak's own escort/visitor procedures are followed by data centre staff who do have authorised access) - carefully scoped to avoid implicating the operator's own general building security; or (iii) excluding physical facility testing from this engagement and instead documenting physical access risk at the shared facility as a topic for Silverpeak's own vendor/facilities risk management and direct conversation with the data centre operator outside the iCAST engagement itself.
Step 5 - Address the legal-position concern rigorously, not informally. The team member's instinct that Hong Kong's legal position may differ from a "UK-only" assumption is exactly correct as a concern, and it should not be left informally unresolved. Consistent with the syllabus principle on jurisdiction-specific legal risk, your firm should not proceed with any physical social engineering element in Hong Kong based on assumptions carried over from UK engagements. This requires confirming (through your firm's own established Hong Kong legal understanding, given this is an iCAST-accredited engagement where such understanding should already exist, or through specific local legal advice if any doubt remains) the local legal position on trespass and physical intrusion testing, and ensuring the authorisation and RoE documentation for this specific engagement explicitly and correctly reflect that position, rather than being inherited unreviewed from unrelated prior UK engagements.
Step 6 - Document the resolution and rationale. Whatever combination of Steps 4's alternatives is ultimately agreed with the Control Group, the rationale, the authorisation boundary reasoning, and the confirmed legal position should be clearly documented in the engagement's scope and RoE documentation, both for internal audit trail purposes and to support any eventual C-RAF/HKMA-related review of the engagement's conduct.
Conclusion: The shared data centre's general building access controls cannot be validly authorised for testing by Silverpeak alone and should not be included without the data centre operator's own explicit, separately obtained consent, given both the authorisation-boundary principle and the added risk to unrelated co-tenants; and the team's informal, unverified assumption about Hong Kong's legal position must be properly and specifically confirmed (not carried over from UK experience) before any physical social engineering proceeds.
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