Analysis and improvement on CHY (t,n) threshold verifiable multi-secret sharing scheme

Lin and Wu have proposed an efficient (t, n) threshold verifiable multi-secret sharing (VMSS) scheme. They claimed that their scheme can counteract the cheating problems between the dealer and any participant. However, He and Wu have shown that Lin and Wu´s scheme is in fact insecure against a cheating participant. Chang, Hwang and Yang proposed an improvement on the Lin-Wu´s scheme. They demonstrated their scheme can solve the problem of Lin-Wu´s scheme. In this paper, we analysis the security of CHY scheme and point out the shared secrets are insecure. In order to enhance the security of CHY scheme, we give an improvement on CHY scheme.