diff --git a/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/util/MessageUtil.java b/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/util/MessageUtil.java
new file mode 100644
index 0000000..ef9b818
--- /dev/null
+++ b/boot/common-framework/src/main/java/com/klaro/acquirecore/framework/util/MessageUtil.java
@@ -0,0 +1,507 @@
+package com.klaro.acquirecore.framework.util;
+
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+/**
+ * Static utility class for message encoding/decoding migrated from legacy/util_msg.c
+ * Uses java.util.Base64 and java.nio.charset for codec operations.
+ */
+public final class MessageUtil {
+
+    public static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
+    public static final Charset EUC_KR_CHARSET = Charset.forName("EUC-KR");
+    public static final Charset ISO_8859_1_CHARSET = StandardCharsets.ISO_8859_1;
+
+    private static final Pattern EMAIL_PATTERN = Pattern.compile(
+            "^[A-Za-z0-9+_.-]+@[A-Za-z0-9.-]+$"
+    );
+    private static final Pattern PHONE_PATTERN = Pattern.compile(
+            "^\\d{2,4}-\\d{3,4}-\\d{4}$|^\\d{10,11}$"
+    );
+    private static final Pattern KOREAN_PHONE_PATTERN = Pattern.compile(
+            "^01[016789]-\\d{3,4}-\\d{4}$"
+    );
+
+    private MessageUtil() {
+        throw new UnsupportedOperationException("Utility class cannot be instantiated");
+    }
+
+    // ==================== Base64 Encoding/Decoding ====================
+
+    /**
+     * Encodes a string to Base64.
+     *
+     * @param input the string to encode
+     * @return the Base64 encoded string
+     */
+    public static String encodeBase64(String input) {
+        Objects.requireNonNull(input, "input must not be null");
+        return Base64.getEncoder().encodeToString(input.getBytes(DEFAULT_CHARSET));
+    }
+
+    /**
+     * Encodes a string to Base64 with specified charset.
+     *
+     * @param input the string to encode
+     * @param charset the charset to use
+     * @return the Base64 encoded string
+     */
+    public static String encodeBase64(String input, Charset charset) {
+        Objects.requireNonNull(input, "input must not be null");
+        Objects.requireNonNull(charset, "charset must not be null");
+        return Base64.getEncoder().encodeToString(input.getBytes(charset));
+    }
+
+    /**
+     * Encodes bytes to Base64.
+     *
+     * @param bytes the bytes to encode
+     * @return the Base64 encoded string
+     */
+    public static String encodeBase64(byte[] bytes) {
+        Objects.requireNonNull(bytes, "bytes must not be null");
+        return Base64.getEncoder().encodeToString(bytes);
+    }
+
+    /**
+     * Decodes a Base64 string to plain string.
+     *
+     * @param encoded the Base64 encoded string
+     * @return the decoded string
+     */
+    public static String decodeBase64(String encoded) {
+        Objects.requireNonNull(encoded, "encoded must not be null");
+        byte[] decoded = Base64.getDecoder().decode(encoded);
+        return new String(decoded, DEFAULT_CHARSET);
+    }
+
+    /**
+     * Decodes a Base64 string to plain string with specified charset.
+     *
+     * @param encoded the Base64 encoded string
+     * @param charset the charset to use for decoding
+     * @return the decoded string
+     */
+    public static String decodeBase64(String encoded, Charset charset) {
+        Objects.requireNonNull(encoded, "encoded must not be null");
+        Objects.requireNonNull(charset, "charset must not be null");
+        byte[] decoded = Base64.getDecoder().decode(encoded);
+        return new String(decoded, charset);
+    }
+
+    /**
+     * Decodes a Base64 string to bytes.
+     *
+     * @param encoded the Base64 encoded string
+     * @return the decoded bytes
+     */
+    public static byte[] decodeBase64ToBytes(String encoded) {
+        Objects.requireNonNull(encoded, "encoded must not be null");
+        return Base64.getDecoder().decode(encoded);
+    }
+
+    /**
+     * Encodes a URL-safe Base64 string.
+     *
+     * @param input the string to encode
+     * @return the URL-safe Base64 encoded string
+     */
+    public static String encodeBase64Url(String input) {
+        Objects.requireNonNull(input, "input must not be null");
+        return Base64.getUrlEncoder().encodeToString(input.getBytes(DEFAULT_CHARSET));
+    }
+
+    /**
+     * Decodes a URL-safe Base64 string.
+     *
+     * @param encoded the URL-safe Base64 encoded string
+     * @return the decoded string
+     */
+    public static String decodeBase64Url(String encoded) {
+        Objects.requireNonNull(encoded, "encoded must not be null");
+        byte[] decoded = Base64.getUrlDecoder().decode(encoded);
+        return new String(decoded, DEFAULT_CHARSET);
+    }
+
+    // ==================== Hex Encoding/Decoding ====================
+
+    /**
+     * Encodes bytes to hexadecimal string.
+     *
+     * @param bytes the bytes to encode
+     * @return the hexadecimal string
+     */
+    public static String encodeHex(byte[] bytes) {
+        Objects.requireNonNull(bytes, "bytes must not be null");
+        StringBuilder sb = new StringBuilder();
+        for (byte b : bytes) {
+            sb.append(String.format("%02x", b));
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Decodes a hexadecimal string to bytes.
+     *
+     * @param hex the hexadecimal string
+     * @return the decoded bytes
+     */
+    public static byte[] decodeHex(String hex) {
+        Objects.requireNonNull(hex, "hex must not be null");
+        if (hex.length() % 2 != 0) {
+            throw new IllegalArgumentException("Hex string must have even length");
+        }
+        int len = hex.length();
+        byte[] data = new byte[len / 2];
+        for (int i = 0; i < len; i += 2) {
+            data[i / 2] = (byte) ((Character.digit(hex.charAt(i), 16) << 4)
+                    + Character.digit(hex.charAt(i + 1), 16));
+        }
+        return data;
+    }
+
+    // ==================== URL Encoding/Decoding ====================
+
+    /**
+     * URL encodes a string using UTF-8.
+     *
+     * @param input the string to encode
+     * @return the URL encoded string
+     */
+    public static String urlEncode(String input) {
+        Objects.requireNonNull(input, "input must not be null");
+        try {
+            return java.net.URLEncoder.encode(input, DEFAULT_CHARSET.name());
+        } catch (java.io.UnsupportedEncodingException e) {
+            throw new RuntimeException("Unsupported encoding", e);
+        }
+    }
+
+    /**
+     * URL decodes a string using UTF-8.
+     *
+     * @param encoded the URL encoded string
+     * @return the decoded string
+     */
+    public static String urlDecode(String encoded) {
+        Objects.requireNonNull(encoded, "encoded must not be null");
+        try {
+            return java.net.URLDecoder.decode(encoded, DEFAULT_CHARSET.name());
+        } catch (java.io.UnsupportedEncodingException e) {
+            throw new RuntimeException("Unsupported encoding", e);
+        }
+    }
+
+    // ==================== String Manipulation ====================
+
+    /**
+     * Masks a string with asterisks, showing only the first and last characters.
+     *
+     * @param input the string to mask
+     * @return the masked string
+     */
+    public static String mask(String input) {
+        return mask(input, 1, 1);
+    }
+
+    /**
+     * Masks a string with asterisks, showing only specified first and last characters.
+     *
+     * @param input the string to mask
+     * @param showFirst number of characters to show at the start
+     * @param showLast number of characters to show at the end
+     * @return the masked string
+     */
+    public static String mask(String input, int showFirst, int showLast) {
+        if (input == null || input.isEmpty()) {
+            return input;
+        }
+        int length = input.length();
+        if (length <= showFirst + showLast) {
+            return input;
+        }
+        StringBuilder sb = new StringBuilder();
+        sb.append(input, 0, showFirst);
+        for (int i = showFirst; i < length - showLast; i++) {
+            sb.append('*');
+        }
+        sb.append(input.substring(length - showLast));
+        return sb.toString();
+    }
+
+    /**
+     * Masks an email address.
+     *
+     * @param email the email to mask
+     * @return the masked email
+     */
+    public static String maskEmail(String email) {
+        if (email == null || !email.contains("@")) {
+            return email;
+        }
+        String[] parts = email.split("@");
+        String localPart = parts[0];
+        String domain = parts[1];
+        if (localPart.length() <= 2) {
+            return mask(localPart, 1, 0) + "@" + domain;
+        }
+        return mask(localPart, 1, 1) + "@" + domain;
+    }
+
+    /**
+     * Masks a phone number.
+     *
+     * @param phone the phone number to mask
+     * @return the masked phone number
+     */
+    public static String maskPhone(String phone) {
+        if (phone == null || phone.isEmpty()) {
+            return phone;
+        }
+        String digitsOnly = phone.replaceAll("[^0-9]", "");
+        if (digitsOnly.length() < 7) {
+            return phone;
+        }
+        int length = digitsOnly.length();
+        String masked = digitsOnly.substring(0, 3) + "****" + digitsOnly.substring(length - 4);
+        if (phone.contains("-")) {
+            return masked.substring(0, 3) + "-" + "****" + "-" + masked.substring(7);
+        }
+        return masked;
+    }
+
+    // ==================== Validation ====================
+
+    /**
+     * Validates if a string is a valid email address.
+     *
+     * @param email the email to validate
+     * @return true if valid, false otherwise
+     */
+    public static boolean isValidEmail(String email) {
+        if (email == null || email.isEmpty()) {
+            return false;
+        }
+        return EMAIL_PATTERN.matcher(email).matches();
+    }
+
+    /**
+     * Validates if a string is a valid phone number.
+     *
+     * @param phone the phone number to validate
+     * @return true if valid, false otherwise
+     */
+    public static boolean isValidPhone(String phone) {
+        if (phone == null || phone.isEmpty()) {
+            return false;
+        }
+        return PHONE_PATTERN.matcher(phone).matches();
+    }
+
+    /**
+     * Validates if a string is a valid Korean phone number.
+     *
+     * @param phone the phone number to validate
+     * @return true if valid, false otherwise
+     */
+    public static boolean isValidKoreanPhone(String phone) {
+        if (phone == null || phone.isEmpty()) {
+            return false;
+        }
+        return KOREAN_PHONE_PATTERN.matcher(phone).matches();
+    }
+
+    /**
+     * Checks if a string is null or empty.
+     *
+     * @param input the string to check
+     * @return true if null or empty
+     */
+    public static boolean isEmpty(String input) {
+        return input == null || input.isEmpty();
+    }
+
+    /**
+     * Checks if a string is null, empty, or whitespace only.
+     *
+     * @param input the string to check
+     * @return true if null, empty, or whitespace only
+     */
+    public static boolean isBlank(String input) {
+        return input == null || input.trim().isEmpty();
+    }
+
+    // ==================== Charset Conversion ====================
+
+    /**
+     * Converts a string from one charset to another.
+     *
+     * @param input the input string
+     * @param fromCharset the source charset
+     * @param toCharset the target charset
+     * @return the converted string
+     */
+    public static String convertCharset(String input, Charset fromCharset, Charset toCharset) {
+        Objects.requireNonNull(input, "input must not be null");
+        Objects.requireNonNull(fromCharset, "fromCharset must not be null");
+        Objects.requireNonNull(toCharset, "toCharset must not be null");
+        byte[] bytes = input.getBytes(fromCharset);
+        return new String(bytes, toCharset);
+    }
+
+    /**
+     * Converts EUC-KR encoded bytes to UTF-8 string.
+     *
+     * @param eucKrBytes the EUC-KR encoded bytes
+     * @return the UTF-8 string
+     */
+    public static String eucKrToUtf8(byte[] eucKrBytes) {
+        Objects.requireNonNull(eucKrBytes, "eucKrBytes must not be null");
+        return new String(eucKrBytes, EUC_KR_CHARSET);
+    }
+
+    /**
+     * Converts UTF-8 string to EUC-KR encoded bytes.
+     *
+     * @param input the UTF-8 string
+     * @return the EUC-KR encoded bytes
+     */
+    public static byte[] utf8ToEucKr(String input) {
+        Objects.requireNonNull(input, "input must not be null");
+        return input.getBytes(EUC_KR_CHARSET);
+    }
+
+    // ==================== Truncation and Padding ====================
+
+    /**
+     * Truncates a string to the specified length.
+     *
+     * @param input the string to truncate
+     * @param maxLength the maximum length
+     * @return the truncated string
+     */
+    public static String truncate(String input, int maxLength) {
+        if (input == null) {
+            return null;
+        }
+        if (input.length() <= maxLength) {
+            return input;
+        }
+        return input.substring(0, maxLength);
+    }
+
+    /**
+     * Pads a string on the left with spaces to reach the specified length.
+     *
+     * @param input the string to pad
+     * @param length the target length
+     * @return the padded string
+     */
+    public static String padLeft(String input, int length) {
+        if (input == null) {
+            input = "";
+        }
+        return String.format("%" + length + "s", input);
+    }
+
+    /**
+     * Pads a string on the right with spaces to reach the specified length.
+     *
+     * @param input the string to pad
+     * @param length the target length
+     * @return the padded string
+     */
+    public static String padRight(String input, int length) {
+        if (input == null) {
+            input = "";
+        }
+        return String.format("%- " + length + "s", input);
+    }
+
+    /**
+     * Pads a string on the left with zeros to reach the specified length.
+     *
+     * @param input the string to pad
+     * @param length the target length
+     * @return the zero-padded string
+     */
+    public static String padLeftWithZeros(String input, int length) {
+        if (input == null) {
+            input = "";
+        }
+        return String.format("%0" + length + "d", Long.parseLong(input));
+    }
+
+    /**
+     * Left pads a numeric string with zeros.
+     *
+     * @param value the numeric value
+     * @param length the target length
+     * @return the zero-padded string
+     */
+    public static String zeroPad(long value, int length) {
+        return String.format("%0" + length + "d", value);
+    }
+
+    // ==================== Byte Array Utilities ====================
+
+    /**
+     * Converts a string to bytes using the default charset.
+     *
+     * @param input the string to convert
+     * @return the bytes
+     */
+    public static byte[] toBytes(String input) {
+        if (input == null) {
+            return null;
+        }
+        return input.getBytes(DEFAULT_CHARSET);
+    }
+
+    /**
+     * Converts a string to bytes using the specified charset.
+     *
+     * @param input the string to convert
+     * @param charset the charset to use
+     * @return the bytes
+     */
+    public static byte[] toBytes(String input, Charset charset) {
+        if (input == null) {
+            return null;
+        }
+        Objects.requireNonNull(charset, "charset must not be null");
+        return input.getBytes(charset);
+    }
+
+    /**
+     * Converts bytes to string using the default charset.
+     *
+     * @param bytes the bytes to convert
+     * @return the string
+     */
+    public static String toString(byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        return new String(bytes, DEFAULT_CHARSET);
+    }
+
+    /**
+     * Converts bytes to string using the specified charset.
+     *
+     * @param bytes the bytes to convert
+     * @param charset the charset to use
+     * @return the string
+     */
+    public static String toString(byte[] bytes, Charset charset) {
+        if (bytes == null) {
+            return null;
+        }
+        Objects.requireNonNull(charset, "charset must not be null");
+        return new String(bytes, charset);
+    }
+}