diff --git a/core/DHT.c b/core/DHT.c
index 01abfdd2..fa36d41f 100644
--- a/core/DHT.c
+++ b/core/DHT.c
@@ -24,6 +24,7 @@
 /*----------------------------------------------------------------------------------*/
 
 #include "DHT.h"
+#include "packets.h"
 #include "ping.h"
 
 /* maximum number of clients stored per friend. */
@@ -472,71 +473,6 @@ static uint64_t add_gettingnodes(IP_Port ip_port)
     return 0;
 }
 
-/* send a ping request, only works if none has been sent to that ip/port
- * in the last 5 seconds. 
- */
-static int pingreq(IP_Port ip_port, uint8_t * public_key)
-{ 
-    /* check if packet is gonna be sent to ourself */
-    if(id_equal(public_key, self_public_key) || is_pinging(ip_port, 0))
-        return 1;
-
-    uint64_t ping_id = add_ping(ip_port);
-    if(ping_id == 0)
-        return 1;
-
-    uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING];
-    uint8_t encrypt[sizeof(ping_id) + ENCRYPTION_PADDING];
-    uint8_t nonce[crypto_box_NONCEBYTES];
-    random_nonce(nonce);
-
-    int len = encrypt_data( public_key, 
-                            self_secret_key, 
-                            nonce, 
-                            (uint8_t *)&ping_id, 
-                            sizeof(ping_id), 
-                            encrypt );
-
-    if(len != sizeof(ping_id) + ENCRYPTION_PADDING)
-        return -1;
-
-    data[0] = 0;
-    memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
-    memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
-    memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
-
-    return sendpacket(ip_port, data, sizeof(data));
-}
-
-/* send a ping response */
-static int pingres(IP_Port ip_port, uint8_t * public_key, uint64_t ping_id)
-{
-    /* check if packet is gonna be sent to ourself */
-    if(id_equal(public_key, self_public_key))
-        return 1;
-
-    uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING];
-    uint8_t encrypt[sizeof(ping_id) + ENCRYPTION_PADDING];
-    uint8_t nonce[crypto_box_NONCEBYTES];
-    random_nonce(nonce);
-
-    int len = encrypt_data( public_key, 
-                            self_secret_key, nonce, 
-                            (uint8_t *)&ping_id, 
-                            sizeof(ping_id), 
-                            encrypt );
-
-    if(len != sizeof(ping_id) + ENCRYPTION_PADDING)
-        return -1;
-
-    data[0] = 1;
-    memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
-    memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
-    memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
-
-    return sendpacket(ip_port, data, sizeof(data));
-}
-
 /* send a getnodes request */
 static int getnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id)
 {
@@ -641,8 +577,8 @@ static int handle_pingreq(uint8_t * packet, uint32_t length, IP_Port source)
     if(len != sizeof(ping_id))
         return 1;
 
-    pingres(source, packet + 1, ping_id);
-    pingreq(source, packet + 1); /* TODO: make this smarter? */
+    send_ping_response(source, (clientid_t*) (packet + 1), ping_id);
+    send_ping_request(source, (clientid_t*) (packet + 1)); /* TODO: make this smarter? */
 
     return 0;
 }
@@ -701,7 +637,7 @@ static int handle_getnodes(uint8_t * packet, uint32_t length, IP_Port source)
     memcpy(&ping_id, plain, sizeof(ping_id));
     sendnodes(source, packet + 1, plain + sizeof(ping_id), ping_id);
 
-    pingreq(source, packet + 1); /* TODO: make this smarter? */
+    send_ping_request(source, (clientid_t*) (packet + 1)); /* TODO: make this smarter? */
 
     return 0;
 }
@@ -741,7 +677,7 @@ static int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
 
     uint32_t i;
     for(i = 0; i < num_nodes; ++i)  {
-        pingreq(nodes_list[i].ip_port, nodes_list[i].client_id);
+        send_ping_request(nodes_list[i].ip_port, (clientid_t*) &nodes_list[i].client_id);
         returnedip_ports(nodes_list[i].ip_port, nodes_list[i].client_id, packet + 1);
     }
 
@@ -831,8 +767,8 @@ static void doDHTFriends(void)
             /* if node is not dead. */
           if (!is_timeout(temp_time, friends_list[i].client_list[j].timestamp, Kill_NODE_TIMEOUT)) {
                 if ((friends_list[i].client_list[j].last_pinged + PING_INTERVAL) <= temp_time) {
-                    pingreq( friends_list[i].client_list[j].ip_port, 
-                             friends_list[i].client_list[j].client_id );
+                    send_ping_request( friends_list[i].client_list[j].ip_port, 
+                                       (clientid_t*) &friends_list[i].client_list[j].client_id );
                     friends_list[i].client_list[j].last_pinged = temp_time;
                 }
                 /* if node is good. */
@@ -869,8 +805,8 @@ static void doClose(void)
         /* if node is not dead. */
         if (!is_timeout(temp_time, close_clientlist[i].timestamp, Kill_NODE_TIMEOUT)) {
             if ((close_clientlist[i].last_pinged + PING_INTERVAL) <= temp_time) {
-                pingreq( close_clientlist[i].ip_port, 
-                         close_clientlist[i].client_id );
+                send_ping_request( close_clientlist[i].ip_port, 
+                                   (clientid_t*) &close_clientlist[i].client_id );
                 close_clientlist[i].last_pinged = temp_time;
             }
             /* if node is good. */
@@ -1151,7 +1087,7 @@ static void punch_holes(IP ip, uint16_t * port_list, uint16_t numports, uint16_t
         /*TODO: improve port guessing algorithm*/
         uint16_t port = port_list[(i/2) % numports] + (i/(2*numports))*((i % 2) ? -1 : 1);
         IP_Port pinging = {ip, htons(port)};
-        pingreq(pinging, friends_list[friend_num].client_id);
+        send_ping_request(pinging, (clientid_t*) &friends_list[friend_num].client_id);
     }
     friends_list[friend_num].punching_index = i;
 }
diff --git a/core/packets.h b/core/packets.h
new file mode 100644
index 00000000..222b1425
--- /dev/null
+++ b/core/packets.h
@@ -0,0 +1,37 @@
+/*
+ * packet.h -- Packet structure
+ *
+ * This file is donated to the Tox Project.
+ * Copyright 2013  plutooo
+ */
+
+typedef struct {
+    uint8_t id[CLIENT_ID_SIZE];
+
+} __attribute__((packed)) clientid_t;
+
+typedef enum {
+    PACKET_PING_REQ = 0,
+    PACKET_PING_RES = 1
+
+} packetid_t;
+
+// Ping packet
+typedef struct {
+    uint8_t    magic;
+    clientid_t client_id;
+    uint8_t    nonce[crypto_box_NONCEBYTES];
+    uint64_t   ping_id;
+    uint8_t    padding[ENCRYPTION_PADDING];
+
+} __attribute__((packed)) pingreq_t;
+
+// Pong packet
+typedef struct {
+    uint8_t    magic;
+    clientid_t client_id;
+    uint8_t    nonce[crypto_box_NONCEBYTES];
+    uint64_t   ping_id;
+    uint8_t    padding[ENCRYPTION_PADDING];
+
+} __attribute__((packed)) pingres_t;
diff --git a/core/ping.c b/core/ping.c
index 8a7d534f..37f1b7ae 100644
--- a/core/ping.c
+++ b/core/ping.c
@@ -8,6 +8,9 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#include "DHT.h"
+#include "net_crypto.h"
+#include "packets.h"
 #include "network.h"
 #include "util.h"
 
@@ -20,76 +23,143 @@ typedef struct {
   uint64_t timestamp;
 } pinged_t;
 
-static pinged_t pings[PING_NUM_MAX];
-static size_t   num_pings;
-static size_t   pos_pings;
+static pinged_t    pings[PING_NUM_MAX];
+static size_t      num_pings;
+static size_t      pos_pings;
+static clientid_t* self_id = (clientid_t*) &self_public_key;
+
+extern uint8_t self_secret_key[crypto_box_SECRETKEYBYTES]; // DHT.c
 
 
-void init_ping() {
-  num_pings = 0;
-  pos_pings = 0;
+void init_ping()
+{
+    num_pings = 0;
+    pos_pings = 0;
 }
 
-static bool is_timeout(uint64_t time) {
-  return (time + PING_TIMEOUT) < now();
+static bool is_timeout(uint64_t time)
+{
+    return (time + PING_TIMEOUT) < now();
 }
 
-static void remove_timeouts() { // O(n)
-  size_t i, id;
-  size_t new_pos = pos_pings;
-  size_t new_num = num_pings;
+static void remove_timeouts() // O(n)
+{
+    size_t i, id;
+    size_t new_pos = pos_pings;
+    size_t new_num = num_pings;
 
-  // Loop through buffer, oldest first
-  for(i=0; i<num_pings; i++) {
-    id = (pos_pings + i) % PING_NUM_MAX;
+    // Loop through buffer, oldest first
+    for (i=0; i<num_pings; i++) {
+        id = (pos_pings + i) % PING_NUM_MAX;
 
-    if(is_timeout(pings[id].timestamp)) {
-      new_pos++;
-      new_num--;
+        if(is_timeout(pings[id].timestamp)) {
+            new_pos++;
+            new_num--;
+        }
+        // Break here because list is sorted.
+        else {
+            break;
+        }
     }
-    // Break here because list is sorted.
-    else
-      break;
-  }
 
   num_pings = new_num;
   pos_pings = new_pos % PING_NUM_MAX;
 }
 
-uint64_t add_ping(IP_Port ipp) { // O(n)
-  size_t p;
-  
-  remove_timeouts();
+uint64_t add_ping(IP_Port ipp) // O(n)
+{
+    size_t p;
 
-  // Remove oldest ping if full buffer
-  if(num_pings == PING_NUM_MAX) {
-    num_pings--;
-    pos_pings = (pos_pings + 1) % PING_NUM_MAX;
-  }
+    remove_timeouts();
 
-  // Insert new ping at end of list
-  p = (pos_pings + num_pings) % PING_NUM_MAX;
-
-  pings[p].ipp       = ipp;
-  pings[p].timestamp = now();
-  pings[p].id        = random_64b();
-
-  num_pings++;
-  return pings[p].id;
-}
-
-bool is_pinging(IP_Port ipp, uint64_t ping_id) { // O(n)
-  size_t i, id;
-
-  remove_timeouts();
-
-  for(i=0; i<num_pings; i++) {
-    id = (pos_pings + i) % PING_NUM_MAX;
-
-    if(ipp_eq(pings[id].ipp, ipp) && pings[id].id == ping_id) {
-      return true;
+    // Remove oldest ping if full buffer
+    if (num_pings == PING_NUM_MAX) {
+        num_pings--;
+        pos_pings = (pos_pings + 1) % PING_NUM_MAX;
     }
-  }
 
-  return false;
+    // Insert new ping at end of list
+    p = (pos_pings + num_pings) % PING_NUM_MAX;
+
+    pings[p].ipp       = ipp;
+    pings[p].timestamp = now();
+    pings[p].id        = random_64b();
+
+    num_pings++;
+    return pings[p].id;
+}
+
+bool is_pinging(IP_Port ipp, uint64_t ping_id) // O(n)
+{
+    size_t i, id;
+
+    if (ipp.ip.i == 0 && ping_id == 0)
+        return false;
+
+    remove_timeouts();
+
+    for (i=0; i<num_pings; i++) {
+        id = (pos_pings + i) % PING_NUM_MAX;
+
+        // ping_id = 0 means match any id
+        if(ipp_eq(pings[id].ipp, ipp) && (ping_id == 0 || pings[id].id == ping_id)) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+int send_ping_request(IP_Port ipp, clientid_t* client_id)
+{
+    pingreq_t pk;
+    int       rc;
+    uint64_t  ping_id;
+
+    if (is_pinging(ipp, 0) || id_eq(client_id, self_id))
+        return 1;
+
+    // Generate random ping_id
+    ping_id = add_ping(ipp);
+
+    pk.magic = PACKET_PING_REQ;
+    id_cpy(&pk.client_id, self_id);     // Our pubkey
+    random_nonce((uint8_t*) &pk.nonce); // Generate random nonce
+
+    // Encrypt ping_id using recipient privkey
+    rc = encrypt_data((uint8_t*) client_id,
+                      self_secret_key,
+                      (uint8_t*) &pk.nonce,
+                      (uint8_t*) &ping_id, sizeof(ping_id),
+                      (uint8_t*) &pk.ping_id);
+
+    if (rc != sizeof(ping_id) + ENCRYPTION_PADDING)
+        return 1;
+
+    return sendpacket(ipp, (uint8_t*) &pk, sizeof(pk));
+}
+
+int send_ping_response(IP_Port ipp, clientid_t* client_id, uint64_t ping_id)
+{
+    pingres_t pk;
+    int       rc;
+
+    if (id_eq(client_id, self_id))
+        return 1;
+
+    pk.magic = PACKET_PING_RES;
+    id_cpy(&pk.client_id, self_id);     // Our pubkey
+    random_nonce((uint8_t*) &pk.nonce); // Generate random nonce
+
+    // Encrypt ping_id using recipient privkey
+    rc = encrypt_data((uint8_t*) client_id,
+                      self_secret_key,
+                      (uint8_t*) &pk.nonce,
+                      (uint8_t*) &ping_id, sizeof(ping_id),
+                      (uint8_t*) &pk.ping_id);
+
+    if (rc != sizeof(ping_id) + ENCRYPTION_PADDING)
+        return 1;
+
+    return sendpacket(ipp, (uint8_t*) &pk, sizeof(pk));
 }
diff --git a/core/ping.h b/core/ping.h
index 1d23df97..f2770a00 100644
--- a/core/ping.h
+++ b/core/ping.h
@@ -10,4 +10,5 @@
 void init_ping();
 uint64_t add_ping(IP_Port ipp);
 bool is_pinging(IP_Port ipp, uint64_t ping_id);
-
+int send_ping_request(IP_Port ipp, clientid_t* client_id);
+int send_ping_response(IP_Port ipp, clientid_t* client_id, uint64_t ping_id);
diff --git a/core/util.c b/core/util.c
index 6b40dad7..d201bcb4 100644
--- a/core/util.c
+++ b/core/util.c
@@ -9,23 +9,37 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#include "network.h"
+#include "DHT.h"
+#include "packets.h"
 
-uint64_t now() {
-  return time(NULL);
+uint64_t now()
+{
+    return time(NULL);
 }
 
-uint64_t random_64b() {
-  uint64_t r;
+uint64_t random_64b()
+{
+    uint64_t r;
 
-  // This is probably not random enough?
-  r = random_int();
-  r <<= 32;
-  r |= random_int();
+    // This is probably not random enough?
+    r = random_int();
+    r <<= 32;
+    r |= random_int();
 
-  return r;
+    return r;
 }
 
-bool ipp_eq(IP_Port a, IP_Port b) {
-  return (a.ip.i == b.ip.i) && (a.port == b.port);
+bool ipp_eq(IP_Port a, IP_Port b)
+{
+    return (a.ip.i == b.ip.i) && (a.port == b.port);
+}
+
+bool id_eq(clientid_t* dest, clientid_t* src)
+{
+    return memcmp(dest, src, sizeof(clientid_t)) == 0;
+}
+
+void id_cpy(clientid_t* dest, clientid_t* src)
+{
+    memcpy(dest, src, sizeof(clientid_t));
 }
diff --git a/core/util.h b/core/util.h
index aab2ead9..a93be08a 100644
--- a/core/util.h
+++ b/core/util.h
@@ -8,3 +8,6 @@
 uint64_t now();
 uint64_t random_64b();
 bool ipp_eq(IP_Port a, IP_Port b);
+bool id_eq(clientid_t* dest, clientid_t* src);
+void id_cpy(clientid_t* dest, clientid_t* src);
+