1School of Mathematics and Computer Science, Damghan University, Damghan, Iran
2School of Engineering, Damghan University, Damghan, Iran
Secret sharing schemes perform an important role in protecting se-cret by sharing it among multiple participants. In 1979, (t; n) threshold secret sharing schemes were proposed by Shamir and Blakley independently. In a (t; n) threshold secret sharing scheme a secret can be shared among n partic- ipants such that t or more participants can reconstruct the secret, but it can not be reconstructed by t - 1 or fewer participants. The proposed schemes by Shamir and Blakley have some drawbacks. Multi-secret and veriable schemes were invented to improve old schemes. We analysis the security of hash based secret sharing schemes, and show that the schemes have some drawbacks. In particular it is shown that the the schemes are not resistant against deceptive behavior by dealer and participants.