package subprotocols; import java.security.SecureRandom; import communication.Communication; import crypto.Crypto; import exceptions.NoSuchPartyException; import oram.Forest; import oram.Metadata; import protocols.Protocol; import struct.Party; import util.M; import util.Util; public class ShiftPIR extends Protocol { SecureRandom sr1; SecureRandom sr2; public ShiftPIR(Communication con1, Communication con2) { super(con1, con2); } public ShiftPIR(Communication con1, Communication con2, SecureRandom sr1, SecureRandom sr2) { super(con1, con2); this.sr1 = sr1; this.sr2 = sr2; } public void reinit(Communication con1, Communication con2, SecureRandom sr1, SecureRandom sr2) { this.con1 = con1; this.con2 = con2; this.sr1 = sr1; this.sr2 = sr2; } public byte[] runP1(byte[][] x, int s) { timer.start(M.online_comp); // TODO: do in place shift byte[][] xp = new byte[x.length][]; for (int i = 0; i < x.length; i++) { xp[i] = x[(i + s) % x.length]; } SSPIR sspir = new SSPIR(con1, con2, sr1, sr2); byte[] z = sspir.runP1(xp); timer.stop(M.online_comp); return z; } public byte[] runP2(byte[][] x, int s) { timer.start(M.online_comp); byte[][] xp = new byte[x.length][]; for (int i = 0; i < x.length; i++) { xp[i] = x[(i + s) % x.length]; } SSPIR sspir = new SSPIR(con1, con2, sr1, sr2); byte[] z = sspir.runP2(xp); timer.stop(M.online_comp); return z; } public void runP3(int l, int t) { timer.start(M.online_comp); SSPIR sspir = new SSPIR(con1, con2, sr1, sr2); sspir.runP3(l, t); timer.stop(M.online_comp); } @Override public void run(Party party, Metadata md, Forest[] forest) { for (int j = 0; j < 100; j++) { int l = 100; int m = 50; byte[][] x = new byte[l][m]; for (int i = 0; i < l; i++) { Crypto.sr.nextBytes(x[i]); } int s = Crypto.sr.nextInt(l); int t = Crypto.sr.nextInt(l); if (party == Party.Eddie) { this.reinit(con1, con2, Crypto.sr_DE, Crypto.sr_CE); con1.write(x); con1.write(s); byte[] out = this.runP1(x, s); con2.write(out); con2.write(x); con2.write(s); } else if (party == Party.Debbie) { this.reinit(con1, con2, Crypto.sr_DE, Crypto.sr_CD); x = con1.readDoubleByteArray(); s = con1.readInt(); byte[] out = this.runP2(x, s); con2.write(out); } else if (party == Party.Charlie) { this.reinit(con1, con2, Crypto.sr_CE, Crypto.sr_CD); this.runP3(l, t); byte[] out1 = con1.read(); x = con1.readDoubleByteArray(); s = con1.readInt(); byte[] out2 = con2.read(); Util.setXor(out1, out2); int index = (s + t) % l; if (!Util.equal(out1, x[index])) System.err.println(j + ": ShiftPIR test failed"); else System.out.println(j + ": ShiftPIR test passed"); } else { throw new NoSuchPartyException(party + ""); } } } @Override public void run(Party party, Metadata md, Forest forest) { } }