package protocols; import java.math.BigInteger; import communication.Communication; import crypto.Crypto; import exceptions.NoSuchPartyException; import oram.Metadata; import oram.Tuple; import protocols.precomputation.PreSSXOT; import protocols.struct.Party; import protocols.struct.PreData; import util.M; import util.P; import util.Timer; import util.Util; public class SSXOT extends Protocol { private int id; private int pid; public SSXOT(Communication con1, Communication con2) { super(con1, con2); this.id = 0; pid = id == 0 ? P.URXOT : P.XOT; } public SSXOT(Communication con1, Communication con2, int id) { super(con1, con2); this.id = id; pid = id == 0 ? P.URXOT : P.XOT; } public Tuple[] runE(PreData predata, Tuple[] m, Timer timer) { timer.start(pid, M.online_comp); // step 1 Tuple[] a = new Tuple[m.length]; for (int i = 0; i < m.length; i++) a[i] = m[predata.ssxot_E_pi[id][i]].xor(predata.ssxot_E_r[id][i]); timer.start(pid, M.online_write); con2.write(pid, a); timer.stop(pid, M.online_write); timer.start(pid, M.online_read); a = con2.readTupleArray(); // step 2 int[] j = con1.readIntArray(); Tuple[] p = con1.readTupleArray(); timer.stop(pid, M.online_read); // step 3 Tuple[] z = new Tuple[j.length]; for (int i = 0; i < j.length; i++) z[i] = a[j[i]].xor(p[i]); timer.stop(pid, M.online_comp); return z; } public void runD(PreData predata, int[] index, Timer timer) { timer.start(pid, M.online_comp); // step 2 int k = index.length; int[] E_j = new int[k]; int[] C_j = new int[k]; Tuple[] E_p = new Tuple[k]; Tuple[] C_p = new Tuple[k]; for (int i = 0; i < k; i++) { E_j[i] = predata.ssxot_E_pi_ivs[id][index[i]]; C_j[i] = predata.ssxot_C_pi_ivs[id][index[i]]; E_p[i] = predata.ssxot_E_r[id][E_j[i]].xor(predata.ssxot_delta[id][i]); C_p[i] = predata.ssxot_C_r[id][C_j[i]].xor(predata.ssxot_delta[id][i]); } timer.start(pid, M.online_write); con2.write(pid, E_j); con2.write(pid, E_p); con1.write(pid, C_j); con1.write(pid, C_p); timer.stop(pid, M.online_write); timer.stop(pid, M.online_comp); } public Tuple[] runC(PreData predata, Tuple[] m, Timer timer) { timer.start(pid, M.online_comp); // step 1 Tuple[] a = new Tuple[m.length]; for (int i = 0; i < m.length; i++) a[i] = m[predata.ssxot_C_pi[id][i]].xor(predata.ssxot_C_r[id][i]); timer.start(pid, M.online_write); con1.write(pid, a); timer.stop(pid, M.online_write); timer.start(pid, M.online_read); a = con1.readTupleArray(); // step 2 int[] j = con2.readIntArray(); Tuple[] p = con2.readTupleArray(); timer.stop(pid, M.online_read); // step 3 Tuple[] z = new Tuple[j.length]; for (int i = 0; i < j.length; i++) z[i] = a[j[i]].xor(p[i]); timer.stop(pid, M.online_comp); return z; } // for testing correctness @Override public void run(protocols.struct.Party party, Metadata md, oram.Forest forest) { Timer timer = new Timer(); for (int j = 0; j < 100; j++) { int n = 100; int k = Crypto.sr.nextInt(50) + 50; int[] index = Util.randomPermutation(k, Crypto.sr); int[] tupleParam = new int[] { 1, 2, 3, 4 }; Tuple[] E_m = new Tuple[n]; Tuple[] C_m = new Tuple[n]; for (int i = 0; i < n; i++) { E_m[i] = new Tuple(tupleParam[0], tupleParam[1], tupleParam[2], tupleParam[3], Crypto.sr); C_m[i] = new Tuple(tupleParam[0], tupleParam[1], tupleParam[2], tupleParam[3], null); } PreData predata = new PreData(); PreSSXOT pressxot = new PreSSXOT(con1, con2, 0); if (party == Party.Eddie) { pressxot.runE(predata, timer); Tuple[] E_out_m = runE(predata, E_m, timer); con2.write(E_m); con2.write(E_out_m); } else if (party == Party.Debbie) { pressxot.runD(predata, n, k, tupleParam, timer); runD(predata, index, timer); con2.write(index); } else if (party == Party.Charlie) { pressxot.runC(predata, timer); Tuple[] C_out_m = runC(predata, C_m, timer); index = con2.readIntArray(); E_m = con1.readTupleArray(); Tuple[] E_out_m = con1.readTupleArray(); boolean pass = true; for (int i = 0; i < index.length; i++) { int input = new BigInteger(1, E_m[index[i]].getA()).intValue(); int output = new BigInteger(1, Util.xor(E_out_m[i].getA(), C_out_m[i].getA())).intValue(); if (input != output) { System.err.println("SSXOT test failed"); pass = false; break; } } if (pass) System.out.println("SSXOT test passed"); } else { throw new NoSuchPartyException(party + ""); } } // timer.print(); } }