Comment on "Cryptanalysis and improvement of multiparty quantum secret   sharing schemes"
  We show that, using Wang et al. attack [T.-y. Wang, Q.-y. Wen, F. Gao, S. Lin, F.-c. Zhu, Phys. Lett. A 373 (2008) 65], the first agent and the last agent cannot eavesdrop all the secret messages in Zhang et al. QSSCM scheme [Z.-j. Zhang, G. Gao, X. Wang, L.-f Han, S.-h. Shi, Opt. Commun. 269 (2007) 418]. In some sense, Wang et al. attack is unsuccessful for Zhang et al. QSSCM scheme. 
Gan Gao
quant-ph