secure dkg without stage 4

destributed-key-generation/src/main/java/Communication/MailHandler.java

@@ -0,0 +1,43 @@
+package Communication;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+import meerkat.protobuf.DKGMessages;
+
+/**
+ * Created by Tzlil on 2/14/2016.
+ */
+public class MailHandler {
+
+    private MessageHandler messageHandler;
+
+    public MailHandler(MessageHandler messageHandler){
+        this.messageHandler = messageHandler;
+    }
+
+    public MessageHandler getMessageHandler(){
+        return messageHandler;
+    }
+
+    public void handel(DKGMessages.Mail mail) throws InvalidProtocolBufferException {
+        switch (mail.getType()){
+            case SECRET:
+                DKGMessages.SecretMessage secretMessage = DKGMessages.SecretMessage.parseFrom(mail.getMessage());
+                messageHandler.handelSecretMessage(mail.getSender(),mail.getDestination()== Network.BROADCAST,secretMessage);
+                break;
+            case COMMITMENT:
+                DKGMessages.CommitmentMessage commitmentMessage = DKGMessages.CommitmentMessage.parseFrom(mail.getMessage());
+                messageHandler.handelCommitmentMessage(mail.getSender(),mail.getDestination()== Network.BROADCAST,commitmentMessage);
+                break;
+            case DONE:
+                DKGMessages.DoneMessage doneMessage = DKGMessages.DoneMessage.parseFrom(mail.getMessage());
+                messageHandler.handelDoneMessage(mail.getSender(),mail.getDestination()== Network.BROADCAST,doneMessage);
+                break;
+            case COMPLAINT:
+                DKGMessages.ComplaintMessage complaintMessage = DKGMessages.ComplaintMessage.parseFrom(mail.getMessage());
+                messageHandler.handelComplaintMessage(mail.getSender(),mail.getDestination()== Network.BROADCAST,complaintMessage);
+                break;
+            default:
+                break;
+        }
+    }
+}

destributed-key-generation/src/main/java/Communication/MessageHandler.java

@@ -0,0 +1,14 @@
+package Communication;
+
+import meerkat.protobuf.DKGMessages;
+
+/**
+ * Created by Tzlil on 2/14/2016.
+ */
+public interface MessageHandler {
+    void handelComplaintMessage(int sender, boolean isBroadcast,DKGMessages.ComplaintMessage complaintMessage);
+    void handelDoneMessage(int sender,  boolean isBroadcast, DKGMessages.DoneMessage doneMessage);
+    void handelCommitmentMessage(int sender,  boolean isBroadcast,DKGMessages.CommitmentMessage commitmentMessage);
+    void handelSecretMessage(int sender,  boolean isBroadcast,DKGMessages.SecretMessage secretMessage);
+    void handelDoubleSecretMessage(int sender,  boolean isBroadcast,DKGMessages.DoubleSecretMessage doubleSecretMessage);
+}

destributed-key-generation/src/main/java/Communication/Network.java

@@ -0,0 +1,70 @@
+package Communication;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import meerkat.protobuf.DKGMessages.*;
+import java.util.Queue;
+import java.util.concurrent.ArrayBlockingQueue;
+/**
+ * Created by Tzlil on 2/7/2016.
+ * JointFeldamn protocol assumes all parties can communicate throw broadcast chanel
+ * and private chanel (for each pair)
+ * this class simulates it
+ */
+public class Network {
+
+    protected final User[] users;
+    protected final int n;
+    protected final Queue<Integer> availableIDs;
+    public static final int BROADCAST = 0;
+
+
+    public Network(int n) {
+        this.n = n;
+        this.users = new User[n];
+        this.availableIDs = new ArrayBlockingQueue<Integer>(n);
+        for (int id = 1; id <= n; id++){
+            availableIDs.add(id);
+        }
+    }
+
+    public User connect(MessageHandler messageHandler){
+        Integer id = availableIDs.poll();
+        if (id == null)
+            return null;
+        users[id - 1] = new User(id,this,new MailHandler(messageHandler));
+        return users[id - 1];
+    }
+
+    protected boolean sendMessage(User sender,int destination,Mail.Type type,Message message){
+        if(destination < 1 || destination > n)
+            return false;
+        User user = users[destination - 1];
+        if (user == null)
+            return false;
+        Mail mail = Mail.newBuilder()
+                .setSender(sender.getID())
+                .setDestination(destination)
+                .setIsPrivate(true)
+                .setType(type)
+                .setMessage(message.toByteString())
+                .build();
+        return user.mailbox.add(mail);
+    }
+
+    protected void sendBroadcast(User sender,Mail.Type type,Message message){
+        User user;
+        Mail mail = Mail.newBuilder()
+                .setSender(sender.getID())
+                .setDestination(BROADCAST)
+                .setIsPrivate(false)
+                .setType(type)
+                .setMessage(message.toByteString())
+                .build();
+        for (int i = 0 ; i < n ; i++){
+            user = users[i];
+            user.mailbox.add(mail);
+        }
+    }
+
+}

destributed-key-generation/src/main/java/Communication/User.java

@@ -0,0 +1,68 @@
+package Communication;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import meerkat.protobuf.DKGMessages;
+
+import java.util.Queue;
+import java.util.concurrent.ArrayBlockingQueue;
+
+/**
+ * Created by Tzlil on 2/14/2016.
+ */
+public class User{
+    protected final MailHandler mailHandler;
+    protected final Queue<DKGMessages.Mail> mailbox;
+    protected final int ID;
+    protected final Thread receiverThread;
+    private final Network network;
+
+    protected User(int ID, Network network, MailHandler mailHandler) {
+        this.mailbox = new ArrayBlockingQueue<DKGMessages.Mail>(2 * network.n * network.n);
+        this.ID = ID;
+        this.mailHandler = mailHandler;
+        this.receiverThread = new Thread(new Receiver());
+        this.network = network;
+    }
+
+    public boolean send(int id, DKGMessages.Mail.Type type, Message message){
+        return network.sendMessage(this,id,type,message);
+    }
+
+    public void broadcast(DKGMessages.Mail.Type type, Message message){
+        network.sendBroadcast(this,type,message);
+    }
+
+    public MessageHandler getMessageHandler(){
+        return mailHandler.getMessageHandler();
+    }
+
+    public int getID() {
+        return ID;
+    }
+    public Thread getReceiverThread(){
+        return receiverThread;
+    }
+    private class Receiver implements Runnable{
+        @Override
+        public void run() {
+            while (true){
+                if (!mailbox.isEmpty()){
+                    try {
+                        mailHandler.handel(mailbox.poll());
+                    } catch (InvalidProtocolBufferException e) {
+                        e.printStackTrace();
+                    }
+                }else{
+                    try {
+                        Thread.sleep(30);
+                    } catch (InterruptedException e) {
+                        // do nothing
+                    }
+                }
+            }
+        }
+    }
+
+
+}

destributed-key-generation/src/main/java/FeldmanVerifiableSecretSharing/VerifiableSecretSharing.java

@@ -1,9 +1,12 @@
 package FeldmanVerifiableSecretSharing;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import Communication.Network;
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.SecretSharing;
+import Communication.User;
-import org.bouncycastle.util.Arrays;
+import ShamirSecretSharing.Polynomial;
-import org.factcenter.qilin.primitives.CyclicGroup;
+import ShamirSecretSharing.SecretSharing;
+import com.google.protobuf.ByteString;
+import meerkat.protobuf.DKGMessages;
+import java.util.Arrays;
 import org.factcenter.qilin.primitives.concrete.Zpstar;
 
 import java.math.BigInteger;
@@ -21,8 +24,7 @@ public class VerifiableSecretSharing extends SecretSharing {
     protected final Zpstar zpstar;
     protected final BigInteger g; // public generator of group
     private final BigInteger y; // y = g ^ x
-    private final BigInteger[] commitments;
+    protected final BigInteger[] commitments;
-
     /**
      * @param p a large prime
      * @param q a large prime dividing p - 1.
@@ -30,8 +32,9 @@ public class VerifiableSecretSharing extends SecretSharing {
      *          the generated group is a subgroup of Zp*.
      *          it must be chosen such that computing discrete logarithms is hard in this group.
      */
-    public VerifiableSecretSharing(int t, int n, BigInteger x, Random random,BigInteger p,BigInteger q,BigInteger g) {
+    public VerifiableSecretSharing(int t, int n, BigInteger x, Random random, BigInteger p, BigInteger q, BigInteger g
-        super(t, n, x, random,q);
+            , User user) {
+        super(t, n, x, random,q,user);
         this.g = g;
         this.zpstar = new Zpstar(p);
         assert (zpstar.contains(g));
@@ -40,6 +43,11 @@ public class VerifiableSecretSharing extends SecretSharing {
         this.y = zpstar.multiply(g,x);
     }
 
+    public VerifiableSecretSharing(int t, int n, BigInteger x, Random random, BigInteger p, BigInteger q, BigInteger g
+            , Network network) {
+        this(t,n,x,random,p,q,g,network.connect(new VerifiableSecretSharingMessageHandler(t)));
+    }
+
     /**
      * @return commitments[i] = g ^ polynomial.coefficients[i]
      */
@@ -102,6 +110,30 @@ public class VerifiableSecretSharing extends SecretSharing {
      * @return copy of commitments
      */
     public BigInteger[] getCommitments() {
-        return Arrays.clone(commitments);
+        return Arrays.copyOf(commitments,commitments.length);
+    }
+
+    public DKGMessages.CommitmentMessage[] prepareCommitmentMessages(){
+        DKGMessages.CommitmentMessage[] commitmentMessages = new DKGMessages.CommitmentMessage[t + 1];
+        for (int k = 0; k <= t ; k ++) {
+            commitmentMessages[k] = DKGMessages.CommitmentMessage.newBuilder()
+                    .setK(k)
+                    .setCommitment(ByteString.copyFrom(commitments[k].toByteArray()))
+                    .build();
+        }
+        return commitmentMessages;
+    }
+
+    protected void computeAndSendCommitments(){
+        DKGMessages.CommitmentMessage[] commitmentMessages = prepareCommitmentMessages();
+        for (int k = 0; k <= t ; k ++){
+            user.broadcast(DKGMessages.Mail.Type.COMMITMENT,commitmentMessages[k]);
+        }
+    }
+
+    @Override
+    public void run() {
+        super.run();
+        computeAndSendCommitments();
     }
 }

destributed-key-generation/src/main/java/FeldmanVerifiableSecretSharing/VerifiableSecretSharingMessageHandler.java

@@ -0,0 +1,40 @@
+package FeldmanVerifiableSecretSharing;
+
+import Communication.Network;
+import ShamirSecretSharing.SecretSharingMessageHandler;
+import meerkat.protobuf.DKGMessages;
+
+
+import java.math.BigInteger;
+import java.util.Arrays;
+
+/**
+ * Created by Tzlil on 2/16/2016.
+ */
+public class VerifiableSecretSharingMessageHandler extends SecretSharingMessageHandler {
+
+    private final BigInteger[] commitments;
+
+    public VerifiableSecretSharingMessageHandler(int t) {
+        this.commitments = new BigInteger[t + 1];
+    }
+
+    public static BigInteger extractCommitment(DKGMessages.CommitmentMessage commitmentMessage){
+        return new BigInteger(commitmentMessage.getCommitment().toByteArray());
+    }
+
+    @Override
+    public void handelCommitmentMessage(int sender,  boolean isBroadcast, DKGMessages.CommitmentMessage commitmentMessage) {
+        if(isBroadcast) { // receive in broadcast only
+            commitments[commitmentMessage.getK()] = extractCommitment(commitmentMessage);
+        }
+    }
+
+    public BigInteger[] getCommitments() {
+        return commitments;
+    }
+
+    public BigInteger getY(){
+        return commitments[0];
+    }
+}

destributed-key-generation/src/main/java/JointFeldmanProtocol/DKG.java

@@ -1,362 +0,0 @@
-package JointFeldmanProtocol;
-
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
-import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
-import com.google.protobuf.ByteString;
-import com.google.protobuf.InvalidProtocolBufferException;
-import org.bouncycastle.util.Arrays;
-import meerkat.protobuf.DKGMessages.*;
-
-import java.math.BigInteger;
-import java.util.HashSet;
-import java.util.Random;
-import java.util.Set;
-import java.util.concurrent.Callable;
-
-/**
- * Created by Tzlil on 2/5/2016.
- *
- * an implementation of a version of Pedersen's distributed key generation protocol
- */
-public class DKG extends VerifiableSecretSharing implements Runnable{
-
-    private final int id;
-    private final Network.User user; // send and receive messages throw network
-
-    private final BigInteger[] ys; // container for y values that
-    private final Polynomial.Point[] shares; // shares[i] equivalent to Si,id in terms of the protocol
-    private final BigInteger[][] commitmentsArray; // commitmentsArray[i] equivalent to Ai in terms of the protocol
-    private final ComplainState[][] complainStates; // complainStates[i][j] == state of Pj's complaint against Pi
-
-    private final Set<Integer> QUAL; // set of all non-disqualified parties
-    private final BigInteger[] commitments; // public verification values
-    private Polynomial.Point share; // final share of the secrete
-    private BigInteger y; // final public value
-
-
-    public DKG(int t, int n, BigInteger x, Random random, BigInteger p, BigInteger q, BigInteger g,Network network) {
-        super(t, n, x, random, p, q, g);
-
-        this.commitmentsArray = new BigInteger[n][t + 1];
-        this.shares = new Polynomial.Point[n];
-        this.user = network.connect(new Handler());
-        this.id = user.getID();
-        this.complainStates = new ComplainState[n][n];
-        this.QUAL = new HashSet<Integer>();
-        this.ys = new BigInteger[n];
-        this.commitments = new BigInteger[t + 1];
-
-        for (int i = 0; i < n; i ++){
-            for (int j = 0 ; j < n ; j ++)
-                complainStates[i][j] = ComplainState.Non;
-        }
-
-    }
-
-    /**
-     * use for simulate real distributed protocol
-     */
-    @Override
-    public void run() {
-        user.getReceiverThread().start();
-        stage1();
-        stage2();
-        stage3();
-        stage4();
-        user.getReceiverThread().interrupt();
-    }
-
-    /**
-     * stage1 according to the protocol
-     *  1. Pi broadcasts Aik for k = 0,...,t.
-     *  2. Pi computes the shares Sij for j = 1,...,n and sends Sij secretly to Pj.
-     */
-    private void stage1(){
-        // for avoiding edge cases, sets commitmentsArray[id - 1]
-        BigInteger[] commitments = super.getCommitments();
-        System.arraycopy(commitments, 0, commitmentsArray[id - 1], 0, commitmentsArray[id - 1].length);
-
-        // broadcasts commitments
-        CommitmentMessage commitment;
-        for (int k = 0; k <= t ; k ++){
-            commitment = CommitmentMessage.newBuilder()
-                            .setK(k)
-                            .setCommitment(ByteString.copyFrom(commitmentsArray[id - 1][k].toByteArray()))
-                            .build();
-            user.broadcast(Mail.Type.COMMITMENT,commitment);
-        }
-
-        // computes and sends shares
-        SecretMessage secret;
-        for (int j = 1; j <= n ; j++ ){
-            if(j != id){
-                secret = SecretMessage.newBuilder()
-                            .setSecret(getShare(j).asMessage())
-                            .build();
-                user.send(j, Mail.Type.SECRET,secret);
-            }
-            else{
-                shares[id - 1] = super.getShare(id);
-            }
-        }
-        while (!isStage1Complete()){
-            try {
-                Thread.sleep(300);
-            } catch (InterruptedException e) {
-                // do nothing
-            }
-        }
-    }
-
-    /**
-     * @return true iff all shares and commitments were received
-     */
-    private boolean isStage1Complete(){
-        for (int i = 1 ; i <= n ; i++){
-            if(shares[i - 1] == null)
-                return false;
-        }
-
-        for (int i = 0; i < commitmentsArray.length; i++){
-            for (int j = 0; j < commitmentsArray[i].length; j++){
-                if(commitmentsArray[i][j] == null)
-                    return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * @param secret
-     * @param i
-     * @return g ^ Sij == verify(j,Ai,zpstar) (mod p)
-     */
-    private boolean isValidSecret(Polynomial.Point secret, int i){
-        int j = secret.x.intValue();
-        return zpstar.multiply(g,secret.y).equals(verify(j,commitmentsArray[i - 1],zpstar));
-    }
-
-    /**
-     * stage2 according to the protocol
-     *  Pj verifies all the shares he received (using isValidSecret)
-     *  if check fails for an index i, Pj broadcasts a complaint against Pi.
-     *  Pj broadcasts yj value at the end of this stage
-     */
-    private void stage2(){
-        ys[id - 1] = super.getY();
-        ComplaintMessage complaint;
-        for (int i = 1; i <= n ; i++ ){
-            if(id != i && !isValidSecret(shares[i - 1],i)) {
-                //message = new Message(Type.Complaint, j)
-                complaint = ComplaintMessage.newBuilder()
-                                .setId(i)
-                                .build();
-                user.broadcast(Mail.Type.COMPLAINT,complaint);
-                complainStates[i - 1][id - 1] = ComplainState.Waiting;
-            }
-        }
-        //broadcast y after all complaints
-        YMessage yMessage = YMessage.newBuilder()
-                .setY(ByteString.copyFrom(super.getY().toByteArray()))
-                .build();
-        user.broadcast(Mail.Type.Y,yMessage);
-
-        while (!isStage2Complete()){
-            try {
-                Thread.sleep(300);
-            } catch (InterruptedException e) {
-                // do nothing
-            }
-        }
-    }
-
-    /**
-     * @return true iff all yi received for i = 1,...,n .
-     */
-    private boolean isStage2Complete() {
-        for (int j = 1; j <= n ; j++) {
-            if (j != id && ys[j - 1] == null)
-                return false;
-        }
-        return true;
-    }
-
-
-    /**
-     * stage3 according to the protocol
-     *  1. if more than t players complain against a player Pi he is disqualified.
-     *  2. Pi broadcasts the share Sij for each complaining player Pj.
-     *  3. if any of the revealed shares fails the verification test, player Pi is disqualified.
-     *  4. set QUAL to be the set of non-disqualified players.
-     */
-    private void stage3(){
-
-        // broadcasts Sij for each complaint against Pid
-        for (int j = 1 ; j <= complainStates[id - 1].length;j++) {
-            switch (complainStates[id - 1][j - 1]) {
-                case Waiting:
-                    user.broadcast(Mail.Type.SECRET, SecretMessage.newBuilder()
-                            .setSecret(getShare(j).asMessage())
-                            .build());
-                    complainStates[id - 1][j - 1] = ComplainState.NonDisqualified;
-                    break;
-                default:
-                    break;
-            }
-        }
-
-        // wait until there is no complaint waiting for answer
-        for (int i = 0; i < complainStates.length;i++){
-            for (int j = 0 ; j < complainStates[i].length;j++){
-                while (complainStates[i][j].equals(ComplainState.Waiting)){
-                    try {
-                        Thread.sleep(300);
-                    } catch (InterruptedException e) {
-                        // do nothing
-                    }
-                }
-            }
-        }
-
-        // add each non-disqualified player to QUAL
-        boolean nonDisqualified;
-        for (int i = 1; i <= complainStates.length;i++){
-            nonDisqualified = true;
-            for (int j = 1 ; j <= complainStates[i - 1].length;j++){
-                nonDisqualified &= complainStates[i - 1][j - 1].equals(ComplainState.Disqualified);
-            }
-            if(nonDisqualified){
-                QUAL.add(i);
-            }
-        }
-    }
-
-    /**
-     * stage4 according to the protocol
-     *  1. public value y is computed as y = multiplication of yi mod p for i in QUAL
-     *  2. public verification values are computed as Ak = multiplication of Aik mod p for i in QUAL for k = 0,...,t
-     *  3. Pj sets is share of the secret as xj = sum of Sij mod q for i in QUAL
-     */
-    private void stage4(){
-        this.y = zpstar.zero();
-        for (int i : QUAL) {
-            this.y = zpstar.add(this.y , ys[i - 1]);
-        }
-        BigInteger commitment;
-        for (int k = 0; k <= t ; k++){
-            commitment = zpstar.zero();
-            for (int i : QUAL) {
-                commitment = zpstar.add(commitment,commitmentsArray[i - 1][k]);
-            }
-            commitments[k] = commitment;
-        }
-
-        BigInteger xj = BigInteger.ZERO;
-        for (int i : QUAL) {
-            xj = xj.add(shares[i - 1].y);
-        }
-        this.share = new Polynomial.Point(BigInteger.valueOf(id) , xj.mod(q));
-    }
-
-    @Override
-    public BigInteger getY() {
-        return y;
-    }
-
-    @Override
-    public BigInteger[] getCommitments() {
-        return Arrays.clone(commitments);
-    }
-
-
-
-
-    private enum ComplainState{
-        Non, Waiting,Disqualified,NonDisqualified
-    }
-
-    private class Handler implements Network.MailHandler {
-
-        private Handler() {}
-
-        void handelSecretMessage(Mail mail) throws InvalidProtocolBufferException {
-            if(shares[mail.getSender() - 1] == null) {
-                SecretMessage secretMessage = SecretMessage.parseFrom(mail.getMessage());
-                Polynomial.Point secret = new Polynomial.Point(secretMessage.getSecret());
-                if(mail.getIsPrivate()){
-                    shares[mail.getSender() - 1] = secret;
-                }else{
-                    int i = mail.getSender();
-                    int j = secret.x.intValue();
-                    switch (complainStates[i - 1][j - 1]){
-                        case Waiting:
-                            if(isValidSecret(secret,i)){
-                                complainStates[i - 1][j - 1] = ComplainState.NonDisqualified;
-                            }else{
-                                complainStates[i - 1][j - 1] = ComplainState.Disqualified;
-                            }
-                            break;
-                        default:
-                            break;
-                    }
-                }
-            }
-        }
-
-        void handelCommitmentMessage(Mail mail) throws InvalidProtocolBufferException {
-            if(!mail.getIsPrivate()) { //broadcast only
-                CommitmentMessage commitmentMessage = CommitmentMessage.parseFrom(mail.getMessage());
-                if (commitmentsArray[mail.getSender() - 1][commitmentMessage.getK()] == null) {
-                    BigInteger commitment = new BigInteger(commitmentMessage.getCommitment().toByteArray());
-                    commitmentsArray[mail.getSender() - 1][commitmentMessage.getK()] = commitment;
-                }
-            }
-        }
-
-        void handelYMessage(Mail mail) throws InvalidProtocolBufferException {
-            if(!mail.getIsPrivate()) { //broadcast only
-                if (ys[mail.getSender() - 1] == null) {
-                    YMessage yMessage = YMessage.parseFrom(mail.getMessage());
-                    BigInteger y = new BigInteger(yMessage.getY().toByteArray());
-                    ys[mail.getSender() - 1] = y;
-                }
-            }
-        }
-
-        void handelComplaintMessage(Mail mail) throws InvalidProtocolBufferException {
-            int id = user.getID();
-            if(!mail.getIsPrivate()) { //broadcast only
-                ComplaintMessage complaintMessage = ComplaintMessage.parseFrom(mail.getMessage());
-                int i = complaintMessage.getId();
-                int j = mail.getSender();
-                switch (complainStates[i - 1][j - 1]){
-                    case Non:
-                        complainStates[i - 1][j - 1] = ComplainState.Waiting;
-                        break;
-                    default:
-                        break;
-                }
-            }
-        }
-
-        @Override
-        public void handel(Mail mail) throws InvalidProtocolBufferException {
-           switch (mail.getType()){
-               case SECRET:
-                   handelSecretMessage(mail);
-                   break;
-               case COMMITMENT:
-                   handelCommitmentMessage(mail);
-                   break;
-               case Y:
-                   handelYMessage(mail);
-                   break;
-               case COMPLAINT:
-                   handelComplaintMessage(mail);
-                   break;
-               default:
-                   break;
-           }
-        }
-    }
-}

destributed-key-generation/src/main/java/JointFeldmanProtocol/DistributedKeyGeneration.java

@@ -0,0 +1,216 @@
+package JointFeldmanProtocol;
+
+import Communication.Network;
+import Communication.User;
+import ShamirSecretSharing.Polynomial;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
+import meerkat.protobuf.DKGMessages.*;
+import org.factcenter.qilin.primitives.concrete.Zpstar;
+
+import java.math.BigInteger;
+import java.util.HashSet;
+import java.util.Random;
+import java.util.Set;
+import java.util.Arrays;
+
+/**
+ * Created by Tzlil on 2/5/2016.
+ *
+ * an implementation of a version of Pedersen's distributed key generation protocol
+ */
+public class DistributedKeyGeneration extends VerifiableSecretSharing implements Runnable{
+
+    private final int id;
+
+    private final Set<Integer> QUAL; // set of all non-disqualified parties
+    private final BigInteger[] finalCommitments; // public verification values
+
+    private Polynomial.Point share; // final share of the secrete
+    private BigInteger y; // final public value
+
+    private final DistributedKeyGenerationMessageHandler handler;
+
+    public DistributedKeyGeneration(int t, int n, BigInteger zi, Random random, BigInteger p, BigInteger q, BigInteger g
+            , User user) {
+        super(t, n, zi, random, p, q, g,user);
+        this.handler = (DistributedKeyGenerationMessageHandler) user.getMessageHandler();
+        this.id = user.getID();
+        this.QUAL = new HashSet<Integer>();
+        this.finalCommitments = new BigInteger[t + 1];
+        Arrays.fill(this.finalCommitments,zpstar.zero());
+    }
+    public DistributedKeyGeneration(int t, int n, BigInteger zi, Random random, BigInteger p, BigInteger q, BigInteger g
+            , Network network) {
+        this(t,n,zi,random,p,q,g,network.connect(new DistributedKeyGenerationMessageHandler(t,n,g,new Zpstar(p))));
+    }
+
+    /**
+     * use for simulate real distributed protocol
+     */
+    @Override
+    public void run() {
+        user.getReceiverThread().start();
+        stage1();
+        stage2();
+        stage3();
+        stage4();
+        user.getReceiverThread().interrupt();
+    }
+
+    /**
+     * stage1 according to the protocol
+     *  1. Pi broadcasts Aik for k = 0,...,t.
+     *  2. Pi computes the shares Sij for j = 1,...,n and sends Sij secretly to Pj.
+     */
+    protected void stage1(){
+        super.run();
+        while (!handler.isStage1Complete()){
+            try {
+                Thread.sleep(300);
+            } catch (InterruptedException e) {
+                // do nothing
+            }
+        }
+    }
+
+    /**
+     * stage2 according to the protocol
+     *  Pj verifies all the shares he received (using isValidSecret)
+     *  if check fails for an index i, Pj broadcasts a complaint against Pi.
+     *  Pj broadcasts yj value at the end of this stage
+     */
+    private void stage2(){
+        ComplaintMessage complaint;
+        for (int i = 1; i <= n ; i++ ){
+            if(id != i && !handler.isValidSecret(i)) {
+                //message = new Message(Type.Complaint, j)
+                complaint = ComplaintMessage.newBuilder()
+                                .setId(i)
+                                .build();
+                user.broadcast(Mail.Type.COMPLAINT,complaint);
+            }
+        }
+        //broadcast done message after all complaints
+        DoneMessage doneMessage = DoneMessage.newBuilder().build();
+        user.broadcast(Mail.Type.DONE,doneMessage);
+
+        while (!handler.isStage2Complete()){
+            try {
+                Thread.sleep(300);
+            } catch (InterruptedException e) {
+                // do nothing
+            }
+        }
+    }
+
+
+
+    protected void answerComplaint(int j){
+        user.broadcast(Mail.Type.SECRET, SecretMessage.newBuilder()
+                .setSecret(getShare(j).asMessage())
+                .build());
+    }
+    /**
+     * stage3 according to the protocol
+     *  1. if more than t players complain against a player Pi he is disqualified.
+     *  2. Pi broadcasts the share Sij for each complaining player Pj.
+     *  3. if any of the revealed shares fails the verification test, player Pi is disqualified.
+     *  4. set QUAL to be the set of non-disqualified players.
+     */
+    private void stage3(){
+        DistributedKeyGenerationMessageHandler.ComplainState[][] complainStates = handler.getComplainStates();
+        // broadcasts Sij for each complaint against Pid
+        for (int j = 1; j <= complainStates[id - 1].length; j++) {
+            switch (complainStates[id - 1][j - 1]) {
+                case Waiting:
+                    answerComplaint(j);
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        // wait until there is no complaint waiting for answer
+        for (int i = 0; i < complainStates.length; i++){
+            for (int j = 0; j < complainStates[i].length; j++){
+                while (complainStates[i][j].equals(DistributedKeyGenerationMessageHandler.ComplainState.Waiting)){
+                    try {
+                        Thread.sleep(300);
+                    } catch (InterruptedException e) {
+                        // do nothing
+                    }
+                }
+            }
+        }
+
+        // add each non-disqualified player to QUAL
+        boolean nonDisqualified;
+        int counter;
+        for (int i = 1; i <= complainStates.length; i++){
+            nonDisqualified = true;
+            counter = 0;
+            for (int j = 1; j <= complainStates[i - 1].length; j++){
+                switch (complainStates[i - 1][j - 1]) {
+                    case Non:
+                        break;
+                    case NonDisqualified:
+                        counter++;
+                    default:
+                        nonDisqualified = false;
+                }
+                if(!nonDisqualified)
+                    break;
+            }
+            if(nonDisqualified && counter <= t){
+                QUAL.add(i);
+            }
+        }
+    }
+
+    /**
+     * stage4 according to the protocol
+     *  1. public value y is computed as y = multiplication of yi mod p for i in QUAL
+     *  2. public verification values are computed as Ak = multiplication of Aik mod p for i in QUAL for k = 0,...,t
+     *  3. Pj sets is share of the secret as xj = sum of Sij mod q for i in QUAL
+     */
+    private void stage4(){
+        this.y = zpstar.zero();
+        for (int i : QUAL) {
+            this.y = zpstar.add(this.y , handler.getY(i));
+        }
+
+        BigInteger[] commitments;
+
+        for (int i : QUAL) {
+            commitments = handler.getCommitments(i);
+            for (int k = 0; k <= t; k++){
+                this.finalCommitments[k] = zpstar.add(this.finalCommitments[k],commitments[k]);
+            }
+        }
+
+        BigInteger xj = BigInteger.ZERO;
+        for (int i : QUAL) {
+            if( i == id){
+                xj = xj.add(super.getShare(i).y);
+            }else{
+                xj = xj.add(handler.getShare(i).y);
+            }
+        }
+        this.share = new Polynomial.Point(BigInteger.valueOf(id) , xj.mod(q));
+    }
+
+    @Override
+    public BigInteger getY() {
+        return y;
+    }
+
+    @Override
+    public BigInteger[] getCommitments() {
+        return Arrays.copyOf(finalCommitments, finalCommitments.length);
+    }
+
+    public Polynomial.Point getShare() {
+        return share;
+    }
+
+}

destributed-key-generation/src/main/java/JointFeldmanProtocol/DistributedKeyGenerationMessageHandler.java

@@ -0,0 +1,161 @@
+package JointFeldmanProtocol;
+
+import Communication.MessageHandler;
+import Communication.Network;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharingMessageHandler;
+import ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.SecretSharingMessageHandler;
+import meerkat.protobuf.DKGMessages;
+import org.factcenter.qilin.primitives.concrete.Zpstar;
+
+import java.math.BigInteger;
+
+/**
+ * Created by Tzlil on 2/16/2016.
+ */
+public class DistributedKeyGenerationMessageHandler implements MessageHandler {
+
+    protected enum ComplainState{
+        Non, Waiting,Disqualified,NonDisqualified
+    }
+
+    protected final VerifiableSecretSharingMessageHandler[] vssHandlers;
+    protected final ComplainState[][] complainStates; // complainStates[i][j] == state of Pj's complaint against Pi
+    protected final BigInteger g;
+    protected final Zpstar zpstar;
+    protected final int n;
+    private final boolean[] doneFlags;
+
+    public DistributedKeyGenerationMessageHandler(int t, int n, BigInteger g, Zpstar zpstar) {
+        this.g = g;
+        this.zpstar = zpstar;
+        this.n = n;
+        this.doneFlags = new boolean[n];
+        this.vssHandlers = new VerifiableSecretSharingMessageHandler[n];
+        for (int i = 1; i <= n ; i++){
+            vssHandlers[i - 1] = new VerifiableSecretSharingMessageHandler(t);
+        }
+        this.complainStates = new ComplainState[n][n];
+        for (int i = 0; i < n; i ++){
+            for (int j = 0 ; j < n ; j ++)
+                this.complainStates[i][j] = ComplainState.Non;
+        }
+    }
+
+    /**
+     * @return true iff all shares and commitments were received
+     */
+    protected boolean isStage1Complete(){
+        for (int i = 1 ; i <= n ; i++){
+            if(vssHandlers[i - 1].getShare() == null)
+                return false;
+        }
+
+        BigInteger[] commitments;
+        for (int i = 0; i < vssHandlers.length; i++){
+            commitments = vssHandlers[i].getCommitments();
+            for (int j = 0; j < commitments.length; j++){
+                if(commitments[j] == null)
+                    return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * @return true iff all flags in doneFlags are true
+     */
+    protected boolean isStage2Complete() {
+        for (int j = 0; j < n ; j++) {
+            if(!doneFlags[j])
+                return false;
+        }
+        return true;
+    }
+
+    @Override
+    public void handelComplaintMessage(int sender,  boolean isBroadcast, DKGMessages.ComplaintMessage complaintMessage) {
+        if(isBroadcast){
+            int i = complaintMessage.getId();
+            int j = sender;
+            switch (complainStates[i - 1][j - 1]){
+                case Non:
+                    complainStates[i - 1][j - 1] = ComplainState.Waiting;
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    @Override
+    public void handelDoneMessage(int sender,  boolean isBroadcast, DKGMessages.DoneMessage doneMessage) {
+        if(isBroadcast)
+            this.doneFlags[sender - 1] = true;
+    }
+
+    @Override
+    public void handelCommitmentMessage(int sender,  boolean isBroadcast, DKGMessages.CommitmentMessage commitmentMessage) {
+        vssHandlers[sender - 1].handelCommitmentMessage(sender, isBroadcast, commitmentMessage);
+    }
+
+
+    /**
+     * @param secret
+     * @param i
+     * @return g ^ Sij == verify(j,Ai,zpstar) (mod p)
+     */
+    private boolean isValidSecret(Polynomial.Point secret, int i){
+        int j = secret.x.intValue();
+        BigInteger[] commitments = vssHandlers[i - 1].getCommitments();
+        return zpstar.multiply(g,secret.y).equals(VerifiableSecretSharing.verify(j,commitments,zpstar));
+    }
+
+    protected boolean isValidSecret(int i){
+        return isValidSecret(getShare(i),i);
+    }
+
+    @Override
+    public void handelSecretMessage(int sender,  boolean isBroadcast, DKGMessages.SecretMessage secretMessage) {
+        vssHandlers[sender - 1].handelSecretMessage(sender, isBroadcast, secretMessage);
+        if(isBroadcast){
+            Polynomial.Point secret = SecretSharingMessageHandler.extractSecret(secretMessage);
+            int i = sender;
+            int j = secret.x.intValue();
+            switch (complainStates[i - 1][j - 1]){
+                case Waiting:
+                    if(isValidSecret(secret,i)){
+                        complainStates[i - 1][j - 1] = ComplainState.NonDisqualified;
+                    }else{
+                        complainStates[i - 1][j - 1] = ComplainState.Disqualified;
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    @Override
+    public void handelDoubleSecretMessage(int sender, boolean isBroadcast, DKGMessages.DoubleSecretMessage doubleSecretMessage) {
+        // ignore
+    }
+
+
+    protected ComplainState[][] getComplainStates() {
+        return complainStates;
+    }
+
+    protected BigInteger getY(int i){
+        return vssHandlers[i - 1].getY();
+    }
+
+    protected BigInteger[] getCommitments(int i){
+        return vssHandlers[i -1].getCommitments();
+    }
+
+    protected Polynomial.Point getShare(int i){
+        return vssHandlers[i-1].getShare();
+    }
+}

destributed-key-generation/src/main/java/JointFeldmanProtocol/Network.java

@@ -1,124 +0,0 @@
-package JointFeldmanProtocol;
-
-import com.google.protobuf.InvalidProtocolBufferException;
-import com.google.protobuf.Message;
-import meerkat.protobuf.DKGMessages.*;
-import java.util.Queue;
-import java.util.concurrent.ArrayBlockingQueue;
-/**
- * Created by Tzlil on 2/7/2016.
- * JointFeldamn protocol assumes all parties can communicate throw broadcast chanel
- * and private chanel (for each pair)
- * this class simulates it
- */
-public class Network {
-
-    private final User[] users;
-    private final int n;
-    private final Queue<Integer> availableIDs;
-
-
-    public Network(int n) {
-        this.n = n;
-        this.users = new User[n];
-        this.availableIDs = new ArrayBlockingQueue<Integer>(n);
-        for (int id = 1; id <= n; id++){
-            availableIDs.add(id);
-        }
-    }
-
-    public User connect(MailHandler messageHandler){
-        Integer id = availableIDs.poll();
-        if (id == null)
-            return null;
-        users[id - 1] = new User(id,messageHandler);
-        return users[id - 1];
-    }
-
-    private boolean sendMessage(User sender,int destination,Mail.Type type,Message message){
-        if(destination < 1 || destination > n)
-            return false;
-        User user = users[destination - 1];
-        if (user == null)
-            return false;
-        Mail mail = Mail.newBuilder()
-                .setSender(sender.getID())
-                .setDestination(destination)
-                .setIsPrivate(true)
-                .setType(type)
-                .setMessage(message.toByteString())
-                .build();
-        return user.mailbox.add(mail);
-    }
-
-    private void sendBroadcast(User sender,Mail.Type type,Message message){
-        User user;
-        int ID = sender.ID;
-        Mail mail = Mail.newBuilder()
-                .setSender(sender.getID())
-                .setDestination(0)
-                .setIsPrivate(false)
-                .setType(type)
-                .setMessage(message.toByteString())
-                .build();
-        for (int i = 0 ; i < n ; i++){
-            if (i + 1 == ID) {
-                continue;
-            }
-            user = users[i];
-            user.mailbox.add(mail);
-        }
-    }
-
-    public class User{
-        private final MailHandler messageHandler;
-        private final Queue<Mail> mailbox;
-        private final int ID;
-        private final Thread receiverThread;
-        public User(int ID, MailHandler messageHandler) {
-            this.mailbox = new ArrayBlockingQueue<Mail>(1 << n);
-            this.ID = ID;
-            this.messageHandler = messageHandler;
-            this.receiverThread = new Thread(new Receiver());
-        }
-
-        public boolean send(int id, Mail.Type type,Message message){
-            return sendMessage(this,id,type,message);
-        }
-        public void broadcast(Mail.Type type,Message message){
-            sendBroadcast(this,type,message);
-        }
-        public int getID() {
-            return ID;
-        }
-        public Thread getReceiverThread(){
-            return receiverThread;
-        }
-        private class Receiver implements Runnable{
-            @Override
-            public void run() {
-                while (true){
-                    if (!mailbox.isEmpty()){
-                        try {
-                            messageHandler.handel(mailbox.poll());
-                        } catch (InvalidProtocolBufferException e) {
-                            e.printStackTrace();
-                        }
-                    }else{
-                        try {
-                            Thread.sleep(30);
-                        } catch (InterruptedException e) {
-                            // do nothing
-                        }
-                    }
-                }
-            }
-        }
-
-
-    }
-
-    public interface MailHandler {
-        public void handel(Mail mail) throws InvalidProtocolBufferException;
-    }
-}

destributed-key-generation/src/main/java/SecureDistributedKeyGeneration/SecureDistributedKeyGeneration.java

@@ -0,0 +1,68 @@
+package SecureDistributedKeyGeneration;
+
+import Communication.Network;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
+import JointFeldmanProtocol.DistributedKeyGeneration;
+import com.google.protobuf.ByteString;
+import meerkat.protobuf.DKGMessages;
+import org.factcenter.qilin.primitives.concrete.Zpstar;
+
+import java.math.BigInteger;
+import java.util.Random;
+
+/**
+ * Created by Tzlil on 2/17/2016.
+ */
+public class SecureDistributedKeyGeneration extends DistributedKeyGeneration {
+
+    VerifiableSecretSharing verifiableSecretSharing;
+
+    public SecureDistributedKeyGeneration(int t, int n, BigInteger zi, Random random, BigInteger p, BigInteger q, BigInteger g
+            ,BigInteger h, Network network) {
+        super(t, n, zi, random, p, q, g, network.connect(new SecureDistributedKeyGenerationMessageHandler(t,n,g,new Zpstar(p))));
+        this.verifiableSecretSharing = new VerifiableSecretSharing(t,n,new BigInteger(q.bitLength(), random).mod(q),random,p,q,h,user);
+    }
+
+    @Override
+    protected void computeAndSendSecrets() {
+        DKGMessages.SecretMessage[] secretMessages1 = prepareSecretMessages();
+        DKGMessages.SecretMessage[] secretMessages2 = verifiableSecretSharing.prepareSecretMessages();
+        DKGMessages.DoubleSecretMessage doubleSecretMessage;
+
+        for (int j = 1; j <= n ; j++ ){
+            doubleSecretMessage = DKGMessages.DoubleSecretMessage.newBuilder()
+                    .setS1(secretMessages1[j - 1])
+                    .setS1(secretMessages2[j - 1])
+                    .build();
+            user.send(j, DKGMessages.Mail.Type.SECRET,doubleSecretMessage);
+        }
+    }
+
+    @Override
+    public DKGMessages.CommitmentMessage[] prepareCommitmentMessages() {
+        DKGMessages.CommitmentMessage[] commitmentMessages = new DKGMessages.CommitmentMessage[t + 1];
+        BigInteger[] commitments2 = verifiableSecretSharing.getCommitments();
+        for (int k = 0; k <= t ; k ++) {
+            commitmentMessages[k] = DKGMessages.CommitmentMessage.newBuilder()
+                    .setK(k)
+                    .setCommitment(ByteString.copyFrom(zpstar.add(commitments[k],commitments2[k]).toByteArray()))
+                    .build();
+        }
+        return commitmentMessages;
+    }
+
+    @Override
+    protected void answerComplaint(int j) {
+        DKGMessages.SecretMessage secretMessage1 = DKGMessages.SecretMessage.newBuilder()
+                .setSecret(getShare(j).asMessage())
+                .build();
+        DKGMessages.SecretMessage secretMessage2 = DKGMessages.SecretMessage.newBuilder()
+                .setSecret(verifiableSecretSharing.getShare(j).asMessage())
+                .build();
+
+        user.broadcast(DKGMessages.Mail.Type.SECRET, DKGMessages.DoubleSecretMessage.newBuilder()
+                .setS1(secretMessage1)
+                .setS2(secretMessage2)
+                .build());
+    }
+}

destributed-key-generation/src/main/java/SecureDistributedKeyGeneration/SecureDistributedKeyGenerationMessageHandler.java

@@ -0,0 +1,61 @@
+package SecureDistributedKeyGeneration;
+
+import Communication.Network;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
+import JointFeldmanProtocol.DistributedKeyGenerationMessageHandler;
+import ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.SecretSharingMessageHandler;
+import meerkat.protobuf.DKGMessages;
+import org.factcenter.qilin.primitives.concrete.Zpstar;
+
+import java.math.BigInteger;
+
+/**
+ * Created by Tzlil on 2/17/2016.
+ */
+public class SecureDistributedKeyGenerationMessageHandler extends DistributedKeyGenerationMessageHandler {
+
+    private final SecretSharingMessageHandler[] ssHandlers;
+    public SecureDistributedKeyGenerationMessageHandler(int t, int n, BigInteger g, Zpstar zpstar) {
+        super(t, n, g, zpstar);
+        this.ssHandlers = new SecretSharingMessageHandler[n];
+    }
+
+    private boolean isValidSecret(Polynomial.Point secret1,Polynomial.Point secret2,int i){
+        int j = secret1.x.intValue();
+        BigInteger[] commitments = vssHandlers[i - 1].getCommitments();
+        return zpstar.multiply(g,zpstar.add(secret1.y,secret2.y)).equals(VerifiableSecretSharing.verify(j,commitments,zpstar));
+    }
+
+    @Override
+    protected boolean isValidSecret(int i) {
+        return isValidSecret(getShare(i),ssHandlers[i - 1].getShare(),i);
+    }
+
+
+    @Override
+    public void handelDoubleSecretMessage(int sender,  boolean isBroadcast, DKGMessages.DoubleSecretMessage doubleSecretMessage) {
+        if(!isBroadcast){
+            this.handelSecretMessage(sender,isBroadcast,doubleSecretMessage.getS1());
+            ssHandlers[sender - 1].handelSecretMessage(sender,isBroadcast,doubleSecretMessage.getS2());
+        }else{
+            Polynomial.Point secret1 = SecretSharingMessageHandler.extractSecret(doubleSecretMessage.getS1());
+            Polynomial.Point secret2 = SecretSharingMessageHandler.extractSecret(doubleSecretMessage.getS2());
+            int i = sender;
+            int j = secret1.x.intValue();
+            switch (complainStates[i - 1][j - 1]){
+                case Waiting:
+                    if(isValidSecret(secret1,secret2,i)){
+                        complainStates[i - 1][j - 1] = ComplainState.NonDisqualified;
+                    }else{
+                        complainStates[i - 1][j - 1] = ComplainState.Disqualified;
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+
+}

destributed-key-generation/src/main/java/ShamirSecretSharing/LagrangePolynomial.java

@@ -1,4 +1,4 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing;
+package ShamirSecretSharing;
 
 import java.math.BigInteger;
 

destributed-key-generation/src/main/java/ShamirSecretSharing/Polynomial.java

@@ -1,4 +1,4 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing;
+package ShamirSecretSharing;
 
 import com.google.protobuf.ByteString;
 import meerkat.protobuf.DKGMessages;
@@ -9,8 +9,8 @@ import java.math.BigInteger;
  * Created by Tzlil on 1/27/2016.
  */
 public class Polynomial implements Comparable<Polynomial> {
-    protected static final Polynomial ZERO = new Polynomial(new BigInteger[]{BigInteger.ZERO}); // neutral for add
+    public static final Polynomial ZERO = new Polynomial(new BigInteger[]{BigInteger.ZERO}); // neutral for add
-    protected static final Polynomial ONE = new Polynomial(new BigInteger[]{BigInteger.ONE});   // neutral for mul
+    public static final Polynomial ONE = new Polynomial(new BigInteger[]{BigInteger.ONE});   // neutral for mul
     private final int degree;
     private final BigInteger[] coefficients;
 
@@ -45,7 +45,7 @@ public class Polynomial implements Comparable<Polynomial> {
 
     @Override
     public String toString() {
-        return "FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests{" +
+        return "ShamirSecretSharing.PolynomialTests{" +
                 "degree=" + degree +
                 ", coefficients=" + java.util.Arrays.toString(coefficients) +
                 '}';
@@ -101,7 +101,7 @@ public class Polynomial implements Comparable<Polynomial> {
 
     /**
      * @param other
-     * @return new FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests of degree max(this degree,other degree) s.t for all x in Z
+     * @return new ShamirSecretSharing.PolynomialTests of degree max(this degree,other degree) s.t for all x in Z
      *         new.image(x) = this.image(x) + other.image(x)
      */
     public Polynomial add(Polynomial other){
@@ -123,7 +123,7 @@ public class Polynomial implements Comparable<Polynomial> {
 
     /**
      * @param constant
-     * @return new FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests of degree this.degree s.t for all x in Z
+     * @return new ShamirSecretSharing.PolynomialTests of degree this.degree s.t for all x in Z
      *         new.image(x) = constant * this.image(x)
      */
     public Polynomial mul(BigInteger constant){
@@ -138,7 +138,7 @@ public class Polynomial implements Comparable<Polynomial> {
 
     /**
      * @param other
-     * @return new FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests of degree this degree + other degree + 1 s.t for all x in Z
+     * @return new ShamirSecretSharing.PolynomialTests of degree this degree + other degree + 1 s.t for all x in Z
      *         new.image(x) = this.image(x) * other.image(x)
      */
     public Polynomial mul(Polynomial other){

destributed-key-generation/src/main/java/ShamirSecretSharing/SecretSharing.java

@@ -1,6 +1,10 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing;
+package ShamirSecretSharing;
 
 
+import Communication.Network;
+import Communication.User;
+import meerkat.protobuf.DKGMessages;
+
 import java.math.BigInteger;
 import java.util.Random;
 
@@ -8,11 +12,12 @@ import java.util.Random;
  * Created by Tzlil on 1/27/2016.
  * an implementation of Shamire's secret sharing scheme
  */
-public class SecretSharing {
+public class SecretSharing implements Runnable{
     protected final int t;
     protected final int n;
     protected final BigInteger q;
 
+    protected final User user; // send and receive messages throw network
     private final Polynomial polynomial;
 
     /**
@@ -24,11 +29,16 @@ public class SecretSharing {
      * @param x      secret, chosen from Zq
      * @param random use for generate random polynomial
      */
-    public SecretSharing(int t, int n, BigInteger x, Random random,BigInteger q) {
+    public SecretSharing(int t, int n, BigInteger x, Random random, BigInteger q, Network network) {
+        this(t,n,x,random,q,network.connect(new SecretSharingMessageHandler()));
+    }
+
+    public SecretSharing(int t, int n, BigInteger x, Random random, BigInteger q, User user) {
         this.q = q;
         this.t = t;
         this.n = n;
         this.polynomial = generateRandomPolynomial(x,random);
+        this.user = user;
     }
 
     /**
@@ -53,18 +63,11 @@ public class SecretSharing {
      *
      * @return polynomial.image(i)%q
      */
-    protected final Polynomial.Point getShare(int i){
+    public Polynomial.Point getShare(int i){
         assert (i > 0 && i <= n);
         return new Polynomial.Point(BigInteger.valueOf(i), polynomial, q);
     }
 
-    /**
-     * use for test only
-     */
-    public Polynomial.Point getShareForTest(int i){
-        return  getShare(i);
-    }
-
     /**
      * @param shares - subset of the original shares
      *
@@ -99,8 +102,31 @@ public class SecretSharing {
         return q;
     }
 
-    protected Polynomial getPolynomial() {
+    public Polynomial getPolynomial() {
 
         return polynomial;
     }
+
+    public DKGMessages.SecretMessage[] prepareSecretMessages(){
+        DKGMessages.SecretMessage[] secretMessages = new DKGMessages.SecretMessage[n];
+        for (int j = 1; j <= n ; j++ ){
+            secretMessages[j - 1] = DKGMessages.SecretMessage.newBuilder()
+                    .setSecret(getShare(j).asMessage())
+                    .build();
+        }
+        return secretMessages;
+    }
+
+    protected void computeAndSendSecrets(){
+        DKGMessages.SecretMessage[] secretMessages = prepareSecretMessages();
+        for (int j = 1; j <= n ; j++ ){
+            user.send(j, DKGMessages.Mail.Type.SECRET,secretMessages[j - 1]);
+        }
+    }
+
+    @Override
+    public void run() {
+        // computes and sends shares
+        computeAndSendSecrets();
+    }
 }

destributed-key-generation/src/main/java/ShamirSecretSharing/SecretSharingMessageHandler.java

@@ -0,0 +1,47 @@
+package ShamirSecretSharing;
+
+import Communication.MessageHandler;
+import Communication.Network;
+import meerkat.protobuf.DKGMessages;
+
+/**
+ * Created by Tzlil on 2/16/2016.
+ */
+public class SecretSharingMessageHandler implements MessageHandler{
+
+    private Polynomial.Point share;
+
+    @Override
+    public void handelComplaintMessage(int sender,  boolean isBroadcast, DKGMessages.ComplaintMessage complaintMessage) {
+        // ignore
+    }
+
+    @Override
+    public void handelDoneMessage(int sender,  boolean isBroadcast, DKGMessages.DoneMessage doneMessage) {
+        // ignore
+    }
+
+    @Override
+    public void handelCommitmentMessage(int sender,  boolean isBroadcast, DKGMessages.CommitmentMessage commitmentMessage) {
+        // ignore
+    }
+
+    @Override
+    public void handelDoubleSecretMessage(int sender,  boolean isBroadcast, DKGMessages.DoubleSecretMessage doubleSecretMessage) {
+        // ignore
+    }
+
+    @Override
+    public void handelSecretMessage(int sender,  boolean isBroadcast, DKGMessages.SecretMessage secretMessage) {
+        if(!isBroadcast)
+            this.share = extractSecret(secretMessage);
+    }
+
+    public static Polynomial.Point extractSecret(DKGMessages.SecretMessage secretMessage){
+        return new Polynomial.Point(secretMessage.getSecret());
+    }
+
+    public Polynomial.Point getShare() {
+        return share;
+    }
+}

destributed-key-generation/src/test/java/FeldmanVerifiableSecretSharing/VerifiableSecretSharingTest.java

@@ -1,6 +1,7 @@
 package FeldmanVerifiableSecretSharing;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import Communication.Network;
+import ShamirSecretSharing.Polynomial;
 import org.factcenter.qilin.primitives.concrete.Zpstar;
 import org.junit.Before;
 import org.junit.Test;
@@ -31,11 +32,12 @@ public class VerifiableSecretSharingTest {
         }while (!g.equals(ZERO) && !zpstar.multiply(g,q).equals(ZERO));// sample from QRZp*
         int t = 8;
         int n = 20;
-
+        Network network;
         verifiableSecretSharingArray = new VerifiableSecretSharing[tests];
         for (int i = 0; i < verifiableSecretSharingArray.length; i++){
+            network = new Network(n);
             verifiableSecretSharingArray[i] = new VerifiableSecretSharing(t,n
-                    ,new BigInteger(q.bitLength(),random).mod(q),random,p,q,g);
+                    ,new BigInteger(q.bitLength(),random).mod(q),random,p,q,g,network);
         }
     }
 
@@ -47,7 +49,7 @@ public class VerifiableSecretSharingTest {
         BigInteger[] commitments = verifiableSecretSharing.getCommitments();
         BigInteger[] verifications = new BigInteger[n];
         for (int i = 1 ; i <= shares.length; i ++){
-            shares[i - 1] = verifiableSecretSharing.getShareForTest(i);
+            shares[i - 1] = verifiableSecretSharing.getShare(i);
             verifications[i - 1] = VerifiableSecretSharing.verify(i,commitments,zpstar);
         }
         BigInteger expected;

destributed-key-generation/src/test/java/JointFeldmanProtocol/DKGTest.java

@@ -1,10 +1,16 @@
 package JointFeldmanProtocol;
 
+import Communication.Network;
+import ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.SecretSharing;
+import FeldmanVerifiableSecretSharing.VerifiableSecretSharing;
 import org.factcenter.qilin.primitives.concrete.Zpstar;
 import org.junit.Before;
 import org.junit.Test;
 
 import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Random;
 
 /**
@@ -13,45 +19,98 @@ import java.util.Random;
 public class DKGTest {
 
 
-    DKG[] dkgs;
+    DistributedKeyGeneration[][] dkgsArrays;
-    Thread[] threads;
+    Thread[][] threadsArrays;
-    int tests = 1 << 10;
+    int tests = 10;
-    Random random;
+    BigInteger p = BigInteger.valueOf(2903);
-
+    BigInteger q = p.subtract(BigInteger.ONE).divide(BigInteger.valueOf(2));
+    BigInteger[] secrets;
     @Before
     public void settings(){
-        BigInteger p = BigInteger.valueOf(2903);
-        BigInteger q = p.subtract(BigInteger.ONE).divide(BigInteger.valueOf(2));
         Zpstar zpstar = new Zpstar(p);
-        random = new Random();
+        Random random = new Random();
         BigInteger g;
+        int t = 9;
+        int n = 20;
         BigInteger ZERO = zpstar.zero();
-        do{
+        dkgsArrays = new DistributedKeyGeneration[tests][n];
-            g = zpstar.sample(random);
+        threadsArrays = new Thread[tests][n];
-        }while (!g.equals(ZERO) && !zpstar.multiply(g,q).equals(ZERO));// sample from QRZp*
+        secrets = new BigInteger[tests];
-        int t = 8;
+        for (int test = 0; test < tests; test++) {
-        int n = 20
+            do {
-                ;
+                g = zpstar.sample(random);
-        Network network = new Network(n);
+            } while (!g.equals(ZERO) && !zpstar.multiply(g, q).equals(ZERO));// sample from QRZp*
-        dkgs = new DKG[n];
+            secrets[test] = BigInteger.ZERO;
-        threads = new Thread[n];
+            Network network = new Network(n);
-        for (int i = 0 ; i < n ; i++) {
+            for (int i = 0; i < n; i++) {
-            dkgs[i] = new DKG(t, n, new BigInteger(q.bitLength(), random).mod(q), random, p, q, g, network);
+                BigInteger secret = new BigInteger(q.bitLength(), random).mod(q);
-            threads[i] = new Thread(dkgs[i]);
+                secrets[test] = secrets[test].add(secret).mod(q);
+                dkgsArrays[test][i] = new DistributedKeyGeneration(t, n,secret, random, p, q, g, network);
+                threadsArrays[test][i] = new Thread(dkgsArrays[test][i]);
+            }
         }
     }
 
-    @Test
+    public void oneTest(Thread[] threads, DistributedKeyGeneration[] dkgs,BigInteger secret) throws Exception {
-    public void DKGTest() throws Exception {
+        for (int i = 0; i < threads.length ; i++){
-        for (int i = 0 ; i < threads.length ; i++){
             threads[i].start();
         }
-        for (int i = 0 ; i < threads.length ; i++){
+        for (int i = 0; i < threads.length ; i++){
             threads[i].join();
         }
+        int t = dkgs[0].getT();
+        int n = dkgs[0].getN();
 
+        Zpstar zpstar = dkgs[0].getZpstar();
+        BigInteger g = dkgs[0].getGenerator();
+
+        // got the right public value
+        assert(zpstar.multiply(g,secret).equals(dkgs[0].getY()));
+
+        // assert all players agreed on the same public value
         for (int i = 0; i < dkgs.length - 1 ; i++){
             assert (dkgs[i].getY().equals(dkgs[i+1].getY()));
         }
+
+        // assert valid verification values
+        BigInteger expected,verification;
+        for (int j = 1; j <= dkgs.length ; j++){
+            expected = zpstar.multiply(g, dkgs[j - 1].getShare().y);
+            verification = VerifiableSecretSharing.verify(j, dkgs[j - 1].getCommitments(),zpstar);
+            assert (expected.equals(verification));
+        }
+
+
+        // restore the secret from t + 1 random shares
+        Polynomial.Point[] shares = new Polynomial.Point[t + 1];
+        for (int i = 0 ; i < shares.length; i++){
+            shares[i] = dkgs[i].getShare();
+        }
+        //List<Integer> indexes = new ArrayList<Integer>(n);
+        //for (int i = 1 ; i <= n; i ++){
+        //    indexes.add(i);
+        //}
+        //Random random = new Random();
+        //int index;
+        //for (int i = 0 ; i < shares.length ; i++){
+        //    index = indexes.remove(random.nextInt(indexes.size()));
+        //    shares[i] = dkgs[index - 1].getShare();
+        //}
+        BigInteger calculatedSecret = SecretSharing.getSecrete(shares).mod(q);
+
+        Polynomial polynomial = Polynomial.ZERO;
+        for (int i = 0 ; i < dkgs.length ; i++){
+            polynomial  = polynomial.add(dkgs[i].getPolynomial());
+        }
+
+        assert (calculatedSecret.equals(secret));
+
+    }
+
+    @Test
+    public void secretSharingTest() throws Exception {
+        for (int i = 0 ; i < dkgsArrays.length; i ++){
+            oneTest(threadsArrays[i],dkgsArrays[i],secrets[i]);
+        }
     }
 }

destributed-key-generation/src/test/java/ShamirSecretSharing/PolynomialTests/AddTest.java

@@ -1,5 +1,5 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests;
+package ShamirSecretSharing.PolynomialTests;
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.Polynomial;
 import org.junit.Before;
 import org.junit.Test;
 

destributed-key-generation/src/test/java/ShamirSecretSharing/PolynomialTests/InterpolationTest.java

@@ -1,6 +1,6 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests;
+package ShamirSecretSharing.PolynomialTests;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.Polynomial;
 import org.junit.Before;
 import org.junit.Test;
 

destributed-key-generation/src/test/java/ShamirSecretSharing/PolynomialTests/MulByConstTest.java

@@ -1,6 +1,6 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests;
+package ShamirSecretSharing.PolynomialTests;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.Polynomial;
 import org.junit.Before;
 import org.junit.Test;
 

destributed-key-generation/src/test/java/ShamirSecretSharing/PolynomialTests/MulTest.java

@@ -1,6 +1,6 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests;
+package ShamirSecretSharing.PolynomialTests;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.Polynomial;
 import org.junit.Before;
 import org.junit.Test;
 

destributed-key-generation/src/test/java/ShamirSecretSharing/PolynomialTests/Utils.java

@@ -1,6 +1,6 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests;
+package ShamirSecretSharing.PolynomialTests;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.Polynomial;
+import ShamirSecretSharing.Polynomial;
 
 import java.math.BigInteger;
 import java.util.Random;

destributed-key-generation/src/test/java/ShamirSecretSharing/SecretSharingTest.java

@@ -1,6 +1,7 @@
-package FeldmanVerifiableSecretSharing.ShamirSecretSharing;
+package ShamirSecretSharing;
 
-import FeldmanVerifiableSecretSharing.ShamirSecretSharing.PolynomialTests.Utils;
+import Communication.Network;
+import Communication.User;
 import org.factcenter.qilin.primitives.CyclicGroup;
 import org.factcenter.qilin.primitives.concrete.Zn;
 import org.junit.Before;
@@ -26,14 +27,17 @@ public class SecretSharingTest {
     public void settings(){
         BigInteger p = BigInteger.valueOf(2903);
         group = new Zn(p);
-        int t = 10;
+        int t = 9;
         int n = 20;
         random = new Random();
         secretSharingArray = new SecretSharing[tests];
         secrets = new BigInteger[tests];
+        Network network;
+
         for (int i = 0; i < secretSharingArray.length; i++){
             secrets[i] = group.sample(random);
-            secretSharingArray[i] = new SecretSharing(t,n,secrets[i],random,p);
+            network = new Network(n);
+            secretSharingArray[i] = new SecretSharing(t,n,secrets[i],random,p,network);
         }
     }
 

meerkat-common/src/main/proto/meerkat/DKGMessages.proto

@@ -8,7 +8,7 @@ message Mail{
     enum Type {
         SECRET = 0;
         COMMITMENT = 1;
-        Y = 2;
+        DONE = 2;
         COMPLAINT = 3;
     }
     int32 sender = 1;
@@ -26,14 +26,17 @@ message SecretMessage {
     Point secret = 1;
 }
 
+message DoubleSecretMessage{
+    SecretMessage s1 = 1;
+    SecretMessage s2 = 2;
+}
+
 message CommitmentMessage{
     int32 k = 1;
     bytes commitment = 2;
 }
 
-message YMessage{
+message DoneMessage{}
-    bytes y = 1;
-}
 
 message ComplaintMessage{
     int32 id = 1;