If you have worked security for high-profile clients before, focus on letting the interviewer know. You do not want to name the high-profile client, showing you are able to maintain confidentialty.

"I understand the nature of this business and how important it is to keep client's information confidential. I can promise I will never talk about any client to my family or friends. They already know that I refuse to divulge information about my job, so they don't ask. I am very good at keeping secrets and privileged information safe."

"I worked in healthcare before changing careers to the security sector. In my previous job, I was bound by HIPAA laws which protect patients' confidentiality. I understand the importance of keeping private information confidential and can assure you I will apply those same principles when working on security detail."