diff --git a/build.json b/build.json
index 72bcc37..9cd3c2a 100644
--- a/build.json
+++ b/build.json
@@ -12,7 +12,7 @@
     },
     "repo": {
         "dependencies": [
-            "me.hatter:commons:3.0",
+            "me.hatter:commons:3.29",
             "org.bouncycastle:bcall-jdk15on:1.60"
         ],
         "testDependencies": [
diff --git a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/EncryptedFile.java b/src/main/java/me/hatter/tools/tinyencrypt/encrypt/EncryptedFile.java
index 42e4418..4804500 100644
--- a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/EncryptedFile.java
+++ b/src/main/java/me/hatter/tools/tinyencrypt/encrypt/EncryptedFile.java
@@ -1,6 +1,7 @@
 package me.hatter.tools.tinyencrypt.encrypt;
 
 import me.hatter.tools.commons.security.crypt.CryptOutputStream;
+import me.hatter.tools.commons.tlv.TlvUtil;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 
 import java.io.*;
@@ -24,7 +25,7 @@ public class EncryptedFile extends FilterOutputStream {
     public EncryptedFile(DataOutputStream rawOut, TinyEncryptMeta tinyEncryptMeta) throws IOException {
         super(getCryptoOutputStream(rawOut, tinyEncryptMeta));
 //        this.tinyEncryptMeta = tinyEncryptMeta;
-        TlvUtil.write(rawOut, TlvUtil.create(0, TinyEncryptMetaUtil.toString(tinyEncryptMeta)));
+        TlvUtil.writeTlv(rawOut, TlvUtil.create(0, TinyEncryptMetaUtil.toString(tinyEncryptMeta)));
         rawOut.flush();
     }
 
diff --git a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/Tlv.java b/src/main/java/me/hatter/tools/tinyencrypt/encrypt/Tlv.java
deleted file mode 100644
index c9d150b..0000000
--- a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/Tlv.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package me.hatter.tools.tinyencrypt.encrypt;
-
-public class Tlv {
-    private int tag;
-    private int length;
-    private byte[] value;
-
-    public int getTag() {
-        return tag;
-    }
-
-    public void setTag(int tag) {
-        this.tag = tag;
-    }
-
-    public int getLength() {
-        return length;
-    }
-
-    public void setLength(int length) {
-        this.length = length;
-    }
-
-    public byte[] getValue() {
-        return value;
-    }
-
-    public void setValue(byte[] value) {
-        this.value = value;
-    }
-}
diff --git a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/TlvUtil.java b/src/main/java/me/hatter/tools/tinyencrypt/encrypt/TlvUtil.java
deleted file mode 100644
index ee2349b..0000000
--- a/src/main/java/me/hatter/tools/tinyencrypt/encrypt/TlvUtil.java
+++ /dev/null
@@ -1,39 +0,0 @@
-package me.hatter.tools.tinyencrypt.encrypt;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-
-public class TlvUtil {
-
-    public static void write(DataOutputStream os, Tlv tlv) throws IOException {
-        os.writeShort(tlv.getTag());
-        os.writeInt(tlv.getLength());
-        os.write(tlv.getValue());
-    }
-
-    public static Tlv read(DataInputStream is) throws IOException {
-        int tag = is.readShort();
-        int length = is.readInt();
-        byte[] bs = new byte[length];
-        is.readFully(bs);
-        Tlv tlv = new Tlv();
-        tlv.setTag(tag);
-        tlv.setLength(length);
-        tlv.setValue(bs);
-        return tlv;
-    }
-
-    public static Tlv create(int tag, String value) {
-        return create(tag, value.getBytes(StandardCharsets.UTF_8));
-    }
-
-    public static Tlv create(int tag, byte[] value) {
-        Tlv tlv = new Tlv();
-        tlv.setTag(tag);
-        tlv.setLength(value.length);
-        tlv.setValue(value);
-        return tlv;
-    }
-}