Quantum steganography with large payload based on entanglement swapping of χ-type entangled states

► We propose a new method to calculate entanglement swapping of X-type entangled states. ► A quantum steganography is proposed based on QSDC with X-type entangled states. ► It manages to own more larger capacity which is increased to eight bits. ► The security of new protocol is great, even for man-in-the-middle and Dos attacks.