What is the advantage of having different subordinate CAs set up in the hierarchical CA model?

Having different subordinate Certificate Authorities (CAs) within a hierarchical CA model provides the distinct advantage of allowing for varied certificate policies, which helps in clearly defining the purpose of each certificate issued. By establishing separate subordinate CAs, an organization can tailor specific policies to cater to different needs, such as distinguishing between internal and external certificates, or between departmental requirements. This capability enhances clarity and governance within the organization, as users can easily understand the role and security assurances associated with each certificate type.

The establishment of different policies for each subordinate CA enables organizations to implement tailored security controls, facilitate easier management of certificates, and ensure compliance with regulatory or operational requirements specific to different areas within the organization. Thus, this differentiation promotes a more organized and effective approach to managing digital certificates, enhancing both security and operational efficiency.