Fig. 4
From: Efficient privacy-preserving variable-length substring match for genome sequence
Example of a secure table lookup when \(w\) = GCT and \(\hat{T}\) = ACGT. Only the lookup for a lower bound is shown. For simplicity, \(R^j_{c,f}\) and \(r^j_f\) are denoted by \(R^j_{c}\) and \(r^j\). \(\mathsf {LF}_{w[i]}(f_i,\hat{T})\) (\(i=0,1,2\)) is computed by \(V_{\mathrm{G}}[0], V_{\mathrm{C}}[2]\), and \(V_{\mathrm{T}}[1]\). V is referenced securely by using R. \(R^0_{\mathrm{G}}[0]\) is computed by \(\sum _{c\in \Sigma } q_c[0] \cdot R_c[0]\). \(R^1_{\mathrm{C}}[2+r^0]\) is computed by \(\sum _{c\in \Sigma } q_c[1] \cdot R_c[2+r^0]\). \(R^2_{\mathrm{T}}[1+r^1]\) is computed by \(\sum _{c\in \Sigma } q_c[2] \cdot R_c[1+r^1]\)