Weak blind quantum signature protocol based on entanglement swapping

Table 2. Criteria of Measurement Base Selection

Operator	$\| C 〉$	$A C$ ’s state	${\| A 〉, \| B 〉}$
$σ_{1}$	$\| ψ_{B D}^{-} 〉$	$\| ψ_{A C}^{-} 〉$	${\| + 〉, \| - 〉}$ or ${\| - 〉, \| + 〉}$
	$\| ϕ_{B D}^{+} 〉$	$\| ϕ_{A C}^{+} 〉$	${\| + 〉, \| + 〉}$ or ${\| - 〉, \| - 〉}$
	$\| ψ_{B D}^{+} 〉$	$\| ψ_{A C}^{+} 〉$	${\| 0 〉, \| 1 〉}$ or ${\| 1 〉, \| 0 〉}$
	$\| ϕ_{B D}^{-} 〉$	$\| ϕ_{A C}^{-} 〉$	${\| 0 〉, \| 0 〉}$ or ${\| 1 〉, \| 1 〉}$
$σ_{2}$	$\| ψ_{B D}^{-} 〉$	$\| ψ_{A C}^{+} 〉$	${\| 0 〉, \| 1 〉}$ or ${\| 1 〉, \| 0 〉}$
	$\| ϕ_{B D}^{+} 〉$	$\| ϕ_{A C}^{-} 〉$	${\| 0 〉, \| 0 〉}$ or ${\| 1 〉, \| 1 〉}$
	$\| ψ_{B D}^{+} 〉$	$\| ψ_{A C}^{-} 〉$	${\| + 〉, \| - 〉}$ or ${\| - 〉, \| + 〉}$
	$\| ϕ_{B D}^{-} 〉$	$\| ϕ_{A C}^{+} 〉$	${\| + 〉, \| + 〉}$ or ${\| - 〉, \| - 〉}$
$σ_{3}$	$\| ψ_{B D}^{-} 〉$	$\| ϕ_{A C}^{-} 〉$	${\| 0 〉, \| 0 〉}$ or ${\| 1 〉, \| 1 〉}$
	$\| ϕ_{B D}^{+} 〉$	$\| ψ_{A C}^{+} 〉$	${\| 0 〉, \| 1 〉}$ or ${\| 1 〉, \| 0 〉}$
	$\| ψ_{B D}^{+} 〉$	$\| ϕ_{A C}^{+} 〉$	${\| + 〉, \| + 〉}$ or ${\| - 〉, \| - 〉}$
	$\| ϕ_{B D}^{-} 〉$	$\| ψ_{A C}^{-} 〉$	${\| + 〉, \| - 〉}$ or ${\| - 〉, \| + 〉}$
$σ_{4}$	$\| ψ_{B D}^{-} 〉$	$\| ϕ_{A C}^{+} 〉$	${\| + 〉, \| + 〉}$ or ${\| - 〉, \| - 〉}$
	$\| ϕ_{B D}^{+} 〉$	$\| ψ_{A C}^{-} 〉$	${\| + 〉, \| - 〉}$ or ${\| - 〉, \| + 〉}$
	$\| ψ_{B D}^{+} 〉$	$\| ϕ_{A C}^{-} 〉$	${\| 0 〉, \| 0 〉}$ or ${\| 1 〉, \| 1 〉}$
	$\| ϕ_{B D}^{-} 〉$	$\| ψ_{A C}^{+} 〉$	${\| 0 〉, \| 1 〉}$ or ${\| 1 〉, \| 0 〉}$