Enhancing the security of quantum secret sharing against multiphoton attack

It is generally believed that nonorthogonal operations which canrealize the state transformation between two nonorthogonal bases mayensure the security of many quantum communication protocols.However, in this paper, we present a powerful attack against quantumsecret sharing protocols of these kinds. Applying entangled photonsas fake signals, Eve can successfully steal the exact informationwithout being revealed. We also give our effective modification toimprove it. Under the suggested checking strategy, even to Eve'smost general attack, it is robust and secure.