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Quantum cryptography was proposed as a counter to the capacity of quantum computers to break classical cryptosystems. A broad subclass of quantum cryptography, called quantum key distribution (QKD), relies on quantum mechanical process for secure distribution of the keys. Quantum channels are inherently noisy, and therefore these protocols will be susceptible to noise as well. In this paper, we study the performance of two QKD protocols — BB84 and E91 under amplitude damping error. We show that while E91 protocol loses its security immediately due to loss of entanglement, the performance of BB84 protocol reduces to random guessing with increasing time. Next, we consider the action of an Eve on the BB84 protocol under amplitude damping noise, who is restricted to guessing the outcome of the protocol only. Under this restriction, we show that Eve can still do better than random guessing when equipped with the characteristics of the noisy channel. Finally, we propose a modification of the BB84 protocol which retains the security of the original protocol, but ensures that Eve cannot get any advantage in guessing the outcome, even with complete channel information.

This paper proposes an Efficient Framework for Quantum Video (EFQV) in quantum computer. EFQV adds time index information into different frames on BRQI (a Quantum Image Representation based on Bitplanes, BRQI) images, and each bitplanes quantum image adds a time index. Complement of Colors (COC) operator, Reverse of Bitplanes (ROB) operator, and Shift of Frames (SOF) operator are designed for EFQV and its operators are tested on the IBM quantum computation framework qiskit. Experimental results show the effectiveness of EFQV and its operations on quantum computing environment. Compared with other frameworks, EFQV has advantages in time complexity and quantum cost.