diff --git a/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/CryptoUtil.java b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/CryptoUtil.java
index 8e28961..cf42471 100644
--- a/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/CryptoUtil.java
+++ b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/CryptoUtil.java
@@ -22,6 +22,12 @@
 
 package com.onixbyte.crypto.util;
 
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+import java.nio.charset.StandardCharsets;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
 /**
  * Utility class for cryptographic operations.
  *
@@ -57,6 +63,36 @@ public final class CryptoUtil {
         return pemKeyText
             .replaceAll("-----BEGIN ((EC )|(RSA ))?(PRIVATE|PUBLIC) KEY-----", "")
             .replaceAll("-----END ((EC )|(RSA ))?(PRIVATE|PUBLIC) KEY-----", "")
-            .replaceAll("\n", "");
+            .replace("\n", "");
+    }
+
+    /**
+     * Computes a Hash-based Message Authentication Code (HMAC) using the SHA-256 algorithm.
+     * <p>
+     * The input payload and secret key are both processed using the {@code UTF-8} charset
+     * to guarantee consistent results across different operating system environments.
+     * The final byte array output is converted into a lower-case hexadecimal string.
+     *
+     * @param payload the raw string data or message content to be authenticated
+     * @param secret  the secret key used to sign the payload
+     * @return a lower-case hexadecimal string representing the computed HMAC-SHA256 signature
+     * @throws NoSuchAlgorithmException if the HmacSHA256 algorithm is not available in the environment
+     * @throws InvalidKeyException      if the provided secret key is inappropriate for
+     *                                  initialising the MAC
+     */
+    public static String hmacSha256(
+        String payload,
+        String secret
+    ) throws NoSuchAlgorithmException, InvalidKeyException {
+        var secretKeySpec = new SecretKeySpec(
+            secret.getBytes(StandardCharsets.UTF_8),
+            "HmacSHA256"
+        );
+
+        var mac = Mac.getInstance("HmacSHA256");
+        mac.init(secretKeySpec);
+
+        var rawHmac = mac.doFinal(payload.getBytes(StandardCharsets.UTF_8));
+        return EncodingUtil.bytesToHex(rawHmac);
     }
 }
diff --git a/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/EncodingUtil.java b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/EncodingUtil.java
new file mode 100644
index 0000000..b105409
--- /dev/null
+++ b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/EncodingUtil.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024-2026 OnixByte
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.onixbyte.crypto.util;
+
+import java.util.HexFormat;
+
+/**
+ * Utility class for handling various data encoding and formatting operations.
+ * <p>
+ * This class provides helper methods to convert raw binary data into standardised
+ * string representations (such as hexadecimal format) commonly required for
+ * cryptographic verification, logging, and data transmission.
+ * <p>
+ * This utility class is stateless and thread-safe.
+ *
+ * @author siujamo
+ */
+public class EncodingUtil {
+
+    /**
+     * Converts an array of bytes into its corresponding hexadecimal string representation.
+     * <p>
+     * Each byte is converted to a two-digit hex string. If the resulting hex value
+     * is a single digit (i.e., less than 16), a leading '0' is automatically prepended
+     * to ensure a consistent and uniform format throughout the output string.
+     *
+     * @param bytes the byte array to be converted, typically the raw output of a cryptographic hash
+     * @return a lower-case hexadecimal string representing the input bytes
+     */
+    public static String bytesToHex(byte[] bytes) {
+        return HexFormat.of().formatHex(bytes);
+    }
+}
diff --git a/common-toolbox/src/main/java/com/onixbyte/common/util/HashUtil.java b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/HashUtil.java
similarity index 99%
rename from common-toolbox/src/main/java/com/onixbyte/common/util/HashUtil.java
rename to crypto-toolbox/src/main/java/com/onixbyte/crypto/util/HashUtil.java
index 5d5aa96..e1edfc0 100644
--- a/common-toolbox/src/main/java/com/onixbyte/common/util/HashUtil.java
+++ b/crypto-toolbox/src/main/java/com/onixbyte/crypto/util/HashUtil.java
@@ -20,7 +20,7 @@
  * SOFTWARE.
  */
 
-package com.onixbyte.common.util;
+package com.onixbyte.crypto.util;
 
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
@@ -66,7 +66,7 @@ import java.util.Optional;
  *
  * @author zihluwang
  * @version 3.0.0
- * @see java.security.MessageDigest
+ * @see MessageDigest
  */
 public final class HashUtil {