untraceable

adj

1. Not able to be traced or tracked down.

   “Then there is bitcoin, the cryptocurrency that has been skyrocketing in value lately. Bitcoin is basically virtual cash — anonymous, untraceable currency stuffed into a mobile wallet.”

   “The core idea of the Nostega paradign is basically camouflaging messages by embedding them in a form of noiseless data by employing either altered authenticated data or legitimate untraceable data, as shown in Section 1.3.”