Semantic Security using a Stronger Soft-Covering Lemma Academic Article uri icon


  • A soft-covering theorem was introduced by Wyner [1, Theorem 6.3] and is the central analysis step for achievability proofs of information theoretic security, resolvability, and channel synthesis. It can also be used for simple achievability proofs in lossy source coding. Recently in [2] we have sharpened the claim of soft-covering by moving away from an expected value analysis. Instead, a random codebook is shown to achieve the soft-covering phenomenon with high probability. The probability of failure is doubly-exponentially small in the block-length, enabling many applications through the union bound. In particular, it can be used to achieve semantic security in wiretap channels without loss of communication rate efficiency, as we demonstrate in [3]. The soft-covering concept says that the distribution induced by selecting an Xn sequence at random from a codebook of sequences and …

publication date

  • January 1, 2016