Tightness conjecture for the quantum-to-classical privacy conversion bound
Let nnn be the number of inputs and ρx\rho_xρx range over quantum locally differentially private mechanisms. Define εinf=εinf(n,ε)\varepsilon_{\inf}=\varepsilon_{\inf}(n,\varepsilon)εinf=εinf(n,ε) as the infi…