Entanglement Enhances Security in Secret Sharing
  We analyze tolerable quantum bit error rates in secret sharing protocols, and show that using entangled encoding states is advantageous in the case when the eavesdropping attacks are local. We also provide a criterion for security in secret sharing -- a parallel of the Csiszar-Korner criterion in single-receiver cryptography. 
Rafal Demkowicz-Dobrzanski, Aditi Sen De, Ujjwal Sen, Maciej   Lewenstein