text: abstract
  low probability of detection (or covert) communication refers to the scenario where information
  must be sent reliably to a receiver, but with low probability of detection by an adversary. recent
  works on the fundamental limits of this communication problem have established achievability and
  converse bounds that are asymptotic in the block length of the code. this paper uses gallager’s random
  coding bound to derive a new achievability bound that is applicable to low probability of detection
  communication in the finite block length regime. further insights are unveiled that are otherwise hidden
  in previous asymptotic analyses.