  Secret sharing schemes create an effective method to safeguard a secret by
dividing it among several participants. By using hash functions and the herding
hashes technique, we first set up a (t+1, n) threshold scheme which is perfect
and ideal, and then extend it to schemes for any general access structure. The
schemes can be further set up as proactive or verifiable if necessary. The
setup and recovery of the secret is efficient due to the fast calculation of
the hash function. The proposed scheme is flexible because of the use of
existing hash functions.
