I love entertaining the possibility that the 4th panel of Kryptos is not actually solvable, and that everyone is spending tons of time and energy trying to know

I love entertaining the possibility that the 4th panel of Kryptos is not actually solvable, and that everyone is spending tons of time and energy trying to know secret information has no practical use, and doesn’t even exist. I feel like that would be a strong artistic statement about the CIA and intelligence agencies in general. Do people reluctantly work to know every secret because it’s actually necessary for security? Or do some people just want to know every secret, and “security” is the handiest excuse for them to pursue that?