How many Trusted Agents (TAs) are recommended at each location for continuity purposes?

In the context of Public Key Infrastructure (PKI), having a sufficient number of Trusted Agents (TAs) at each location is crucial for maintaining operational continuity and resilience. The recommendation of three TAs is based on the need for redundancy and the ability to ensure that services can continue uninterrupted, even in the event that one agent is unavailable due to unforeseen circumstances.

Having three TAs allows an organization to effectively manage key registration and certificate issuance processes while providing a buffer against potential failures or absences. With an odd number of TAs, it simplifies decision-making processes regarding key management and ensures that there can always be a majority opinion, which is important for critical decisions or actions that need consensus.

This structure not only enhances reliability but also allows for better distribution of workload among agents, which can lead to improved efficiency in operations. In the case of staffing issues, training, or urgent situations, the presence of multiple agents allows for coverage, ensuring that the PKI remains functional and secure.

Thus, the recommendation of three TAs strikes a balance between too few agents, which could lead to single points of failure, and too many, which could complicate management without providing significant additional security or efficiency benefits.