WordNet sense 1 (not accessible to view):

out of sight

WordNet sense 2 (impossible or nearly impossible to see; imperceptible by the eye):

unseeable

WordNet sense 3 (not open or public; kept private or not revealed):

secret

WordNet sense 4 (with your identity concealed):

incognito

WordNet sense 5 (designed to elude detection):

hidden

WordNet sense 6 (difficult to find):

obscure