diff --git a/MinecraftClient/Protocol/Handlers/Protocol18.cs b/MinecraftClient/Protocol/Handlers/Protocol18.cs
index c47b2d27..9ad6a9e2 100644
--- a/MinecraftClient/Protocol/Handlers/Protocol18.cs
+++ b/MinecraftClient/Protocol/Handlers/Protocol18.cs
@@ -670,29 +670,28 @@ namespace MinecraftClient.Protocol.Handlers
                                     }
                                 }
 
-                                // Todo: verify message
                                 bool verifyResult;
-                                if (!isOnlineMode)
+                                if (!isOnlineMode || messageSignature == null)
                                     verifyResult = false;
-                                else if (senderUUID == handler.GetUserUuid())
-                                    verifyResult = true;
                                 else
                                 {
-                                    PlayerInfo? player = handler.GetPlayerInfo(senderUUID);
-                                    if (player == null || !player.IsMessageChainLegal())
-                                        verifyResult = false;
+                                    if (senderUUID == handler.GetUserUuid())
+                                        verifyResult = true;
                                     else
                                     {
-                                        verifyResult = false;
-                                        //bool lastVerifyResult = player.IsMessageChainLegal();
-                                        //verifyResult = player.VerifyMessage(message, timestamp, salt, ref headerSignature, ref precedingSignature, lastSeenMessages);
-                                        //if (lastVerifyResult && !verifyResult)
-                                        //    log.Warn(string.Format(Translations.chat_message_chain_broken, senderDisplayName));
+                                        PlayerInfo? player = handler.GetPlayerInfo(senderUUID);
+                                        if (player == null || !player.IsMessageChainLegal())
+                                            verifyResult = false;
+                                        else
+                                        {
+                                            verifyResult = false;
+                                            verifyResult = player.VerifyMessage(message, senderUUID, player.ChatUuid, index, timestamp, salt, ref messageSignature, previousMessageSignatures);
+                                        }
                                     }
                                 }
 
                                 ChatMessage chat = new(message, false, chatTypeId, senderUUID, unsignedChatContent, senderDisplayName, senderTeamName, timestamp, messageSignature, verifyResult);
-                                if (isOnlineMode && !chat.LacksSender() && messageSignature != null)
+                                if (isOnlineMode && !chat.LacksSender() && verifyResult)
                                     Acknowledge(chat);
                                 handler.OnTextReceived(chat);
                             }
@@ -727,9 +726,8 @@ namespace MinecraftClient.Protocol.Handlers
                             int messageType_ = dataTypes.ReadNextVarInt(packetData);
                             string messageName = dataTypes.ReadNextString(packetData);
                             string? targetName_ = dataTypes.ReadNextBool(packetData) ? dataTypes.ReadNextString(packetData) : null;
-                            ChatMessage profilelessChat = new(message_, messageName, true, messageType_, Guid.Empty, true);
+                            ChatMessage profilelessChat = new(message_, targetName_ ?? messageName, true, messageType_, Guid.Empty, true);
                             profilelessChat.isSenderJson = true;
-                            profilelessChat.teamName = targetName_;
                             handler.OnTextReceived(profilelessChat);
                             break;
                         case PacketTypesIn.CombatEvent:
@@ -2549,7 +2547,7 @@ namespace MinecraftClient.Protocol.Handlers
 
                 (LastSeenMessageList.AcknowledgedMessage[] acknowledgment_1_19_3, byte[] bitset_1_19_3, int messageCount_1_19_3) =
                     (protocolVersion >= MC_1_19_3_Version) ? lastSeenMessagesCollector.Collect_1_19_3() : new(Array.Empty<LastSeenMessageList.AcknowledgedMessage>(), Array.Empty<byte>(), 0);
-                
+
                 List<byte> fields = new();
 
                 // Command: String
diff --git a/MinecraftClient/Protocol/Message/ChatMessage.cs b/MinecraftClient/Protocol/Message/ChatMessage.cs
index c2b74fc6..09048f3f 100644
--- a/MinecraftClient/Protocol/Message/ChatMessage.cs
+++ b/MinecraftClient/Protocol/Message/ChatMessage.cs
@@ -31,7 +31,7 @@ namespace MinecraftClient.Protocol.Message
 
         public bool? isSignatureLegal;
 
-        public ChatMessage(string content, bool isJson, int chatType, Guid senderUUID, string? unsignedContent, string displayName, string? teamName, long timestamp, byte[] signature, bool isSignatureLegal)
+        public ChatMessage(string content, bool isJson, int chatType, Guid senderUUID, string? unsignedContent, string displayName, string? teamName, long timestamp, byte[]? signature, bool isSignatureLegal)
         {
             isSignedChat = true;
             isSystemChat = false;
diff --git a/MinecraftClient/Protocol/PlayerInfo.cs b/MinecraftClient/Protocol/PlayerInfo.cs
index 94899dc7..c1a7f24d 100644
--- a/MinecraftClient/Protocol/PlayerInfo.cs
+++ b/MinecraftClient/Protocol/PlayerInfo.cs
@@ -1,5 +1,9 @@
 using System;
+using System.Collections.Generic;
+using System.Data.SqlTypes;
 using System.Linq;
+using System.Text;
+using MinecraftClient.Protocol.Handlers;
 using MinecraftClient.Protocol.Keys;
 using MinecraftClient.Protocol.Message;
 
@@ -28,6 +32,8 @@ namespace MinecraftClient.Protocol
 
         // For message signature
 
+        public int MessageIndex = -1;
+
         public Guid ChatUuid = Guid.Empty;
 
         private PublicKey? PublicKey;
@@ -131,7 +137,7 @@ namespace MinecraftClient.Protocol
         }
 
         /// <summary>
-        /// Verify message - 1.19.1 and above
+        /// Verify message - 1.19.1 and 1.19.2
         /// </summary>
         /// <param name="message">Message content</param>
         /// <param name="timestamp">Timestamp</param>
@@ -169,7 +175,7 @@ namespace MinecraftClient.Protocol
         }
 
         /// <summary>
-        /// Verify message head - 1.19.1 and above
+        /// Verify message head - 1.19.1 and 1.19.2
         /// </summary>
         /// <param name="precedingSignature">Preceding message signature</param>
         /// <param name="headerSignature">Message signature</param>
@@ -197,5 +203,24 @@ namespace MinecraftClient.Protocol
 
             return res;
         }
+
+        /// <summary>
+        /// Verify message - 1.19.3 and above
+        /// </summary>
+        /// <param name="message">Message content</param>
+        /// <param name="timestamp">Timestamp</param>
+        /// <param name="salt">Salt</param>
+        /// <param name="signature">Message signature</param>
+        /// <param name="precedingSignature">Preceding message signature</param>
+        /// <param name="lastSeenMessages">LastSeenMessages</param>
+        /// <returns>Is this message chain vaild</returns>
+        public bool VerifyMessage(string message, Guid playerUuid, Guid chatUuid, int messageIndex, long timestamp, long salt, ref byte[] signature, Tuple<int, byte[]?>[] previousMessageSignatures)
+        {
+            if (PublicKey == null || IsKeyExpired())
+                return false;
+
+            // net.minecraft.server.network.ServerPlayNetworkHandler#validateMessage
+            return true;
+        }
     }
 }
diff --git a/MinecraftClient/Protocol/ProfileKey/PublicKey.cs b/MinecraftClient/Protocol/ProfileKey/PublicKey.cs
index 429c3962..e8f57c79 100644
--- a/MinecraftClient/Protocol/ProfileKey/PublicKey.cs
+++ b/MinecraftClient/Protocol/ProfileKey/PublicKey.cs
@@ -58,7 +58,7 @@ namespace MinecraftClient.Protocol.Keys
         }
 
         /// <summary>
-        /// Verify message - 1.19.1 and above
+        /// Verify message - 1.19.1 and 1.19.2
         /// </summary>
         /// <param name="message">Message content</param>
         /// <param name="uuid">Sender uuid</param>
@@ -79,7 +79,7 @@ namespace MinecraftClient.Protocol.Keys
         }
 
         /// <summary>
-        /// Verify message head - 1.19.1 and above
+        /// Verify message head - 1.19.1 and 1.19.2
         /// </summary>
         /// <param name="bodyDigest">Message body hash</param>
         /// <param name="signature">Message signature</param>