Perfect indistinguishability

Definition

An Encryption scheme is perfectly indistinguishable if m0,m1\forall m_0, m_1 \in \mathcal{M}, c𝒞\forall c \in \mathcal{C}, Pr[Enc𝐊(m0)=c]=Pr[Enc𝐊(m1)=c]\Pr[\operatorname{Enc}_\mathbf{K}(m_0)=c] = \Pr[\operatorname{Enc}_\mathbf{K}(m_1)=c]