ABSTRACT
This chapter discusses secret sharing methods. Secret sharing or secret splitting are methods for the distribution of a secret among the group participants, each of whom is given a chunk of the secret. Reconstruction is only possible when sufficient shares are combined. Encryptions have been traditionally used to keep information confidential. But some critical information such as missile launch code requires reliability as well as confidentiality. It could be disastrous if it is lost. Traditional encryption methods are not suitable for achieving high levels of reliability because keeping multiple copies of the same information encrypted in different locations may lead to additional attacks. If the secret is encoded using all the coordinates, even if they are random, then an insider gains information about the secret since he knows it must lie on his plane. If an insider can gain any more knowledge about the secret than an outsider can, then the system no longer has information theoretic security.
