Comment on "Quantum string seal is insecure"
  Recently an attack strategy was proposed by Chau [H. F. Chau, quant-ph/0602099 v3], which was claimed to be able to break all quantum string seal protocols, including the one proposed by He [G. P. He, Int. J. Quant. Inform. 4, 677 (2006)]. Here it will be shown that the information obtained in He's protocol by the attack is trivial. Thus Chau's conclusion that all quantum string seals are insecure is wrong. It will also be shown that some other claims in Chau's paper are inaccurate either. 
Guang Ping He