Two Novel and Secure Quantum ANDOS Schemes

A vendor has several secrets which he regards as of equal worth and importance. He is willing to sell any of these secrets to a buyer. The bargain is said to be secure when the following two conditions are satisfied: 1) the buyer can only obtain one secret if he pays for only one secret, and 2) the vendor will not be able to find out which secret the buyer picked. This cryptographic problem is customarily called all-or-nothing disclosure of secrets (ANDOS). Previous ANDOS schemes have a few defects: neither the number of the secrets is restricted within narrow limits, nor the security is desirable. In this paper, we propose two new and novel ANDOS protocols in quantum computing environment. The first protocol is shown to be as secure as a classical one. The second protocol is based on unambiguous state discrimination, which is proven to be secure in quantum world. Moreover, all our schemes have no limitation on the number of the secrets to be sold.