diff --git a/Project/Src/com/cscn/Zuc256Core.java b/Project/Src/com/cscn/Zuc256Core.java
index db73a16..eb5d84d 100644
--- a/Project/Src/com/cscn/Zuc256Core.java
+++ b/Project/Src/com/cscn/Zuc256Core.java
@@ -4,9 +4,11 @@ package com.cscn;
 import static com.cscn.Zuc256Util.L1;
 import static com.cscn.Zuc256Util.L2;
 import static com.cscn.Zuc256Util.add31;
+import static com.cscn.Zuc256Util.add31_pair;
 import static com.cscn.Zuc256Util.makeU31;
 import static com.cscn.Zuc256Util.makeU32;
 import static com.cscn.Zuc256Util.rot31;
+import static com.cscn.Zuc256Util.rot31_pair;
 
 /**
  * ZUC-256 核心：状态初始化、密钥字生成、密钥流生成。
diff --git a/Project/Src/com/cscn/Zuc256MacCtx.java b/Project/Src/com/cscn/Zuc256MacCtx.java
index 8e36886..2a97fd4 100644
--- a/Project/Src/com/cscn/Zuc256MacCtx.java
+++ b/Project/Src/com/cscn/Zuc256MacCtx.java
@@ -1,15 +1,31 @@
 package com.cscn;
 
 /**
- * MAC上下文类
+ * MAC上下文类（JavaCard版，int 拆分为两个 short）
  */
 public final class Zuc256MacCtx {
-    int[] LFSR = new int[16];
-    int R1;
-    int R2;
+    // LFSR: 原本 int[16]，拆成 hi/lo 各 16 short
+    short[] LFSR_hi = new short[16];
+    short[] LFSR_lo = new short[16];
+
+    // R1、R2: 原本 int，拆成 hi/lo
+    short R1_hi;
+    short R1_lo;
+    short R2_hi;
+    short R2_lo;
+
+    // 缓冲区
     byte[] buf = new byte[4];
-    int buflen;
-    int[] T = new int[4];
-    int[] K0 = new int[4];
-    int macbits;
+    short buflen;
+
+    // T: 原本 int[4]，拆成 hi/lo
+    short[] T_hi = new short[4];
+    short[] T_lo = new short[4];
+
+    // K0: 原本 int[4]，拆成 hi/lo
+    short[] K0_hi = new short[4];
+    short[] K0_lo = new short[4];
+
+    // macbits: 原本 int，改成 short 足够
+    short macbits;
 }
diff --git a/Project/Src/com/cscn/Zuc256State.java b/Project/Src/com/cscn/Zuc256State.java
index 7db919a..8e65c5f 100644
--- a/Project/Src/com/cscn/Zuc256State.java
+++ b/Project/Src/com/cscn/Zuc256State.java
@@ -1,10 +1,16 @@
 package com.cscn;
 
 /**
- * ZUC状态类
+ * ZUC状态类（JavaCard版，int 拆为 hi/lo short）
  */
 public final class Zuc256State {
-    int[] LFSR = new int[16];  // 线性反馈移位寄存器
-    int R1;                    // 寄存器1
-    int R2;                    // 寄存器2
+    // LFSR: 原 int[16] -> hi/lo 各 16
+    public short[] LFSR_hi = new short[16];
+    public short[] LFSR_lo = new short[16];
+
+    // R1, R2: 原 int -> hi/lo
+    public short R1_hi;
+    public short R1_lo;
+    public short R2_hi;
+    public short R2_lo;
 }
diff --git a/Project/Src/com/cscn/Zuc256Tables.java b/Project/Src/com/cscn/Zuc256Tables.java
index 49b3dc6..00a53c5 100644
--- a/Project/Src/com/cscn/Zuc256Tables.java
+++ b/Project/Src/com/cscn/Zuc256Tables.java
@@ -9,7 +9,7 @@ public final class Zuc256Tables {
     private Zuc256Tables() {}
 
     // S盒：S0, S1
-    public static final int[] S0 = {
+    public static final short[] S0 = {
         0x3e,0x72,0x5b,0x47,0xca,0xe0,0x00,0x33,0x04,0xd1,0x54,0x98,0x09,0xb9,0x6d,0xcb,
         0x7b,0x1b,0xf9,0x32,0xaf,0x9d,0x6a,0xa5,0xb8,0x2d,0xfc,0x1d,0x08,0x53,0x03,0x90,
         0x4d,0x4e,0x84,0x99,0xe4,0xce,0xd9,0x91,0xdd,0xb6,0x85,0x48,0x8b,0x29,0x6e,0xac,
@@ -28,7 +28,7 @@ public final class Zuc256Tables {
         0x8d,0x27,0x1a,0xdb,0x81,0xb3,0xa0,0xf4,0x45,0x7a,0x19,0xdf,0xee,0x78,0x34,0x60
     };
 
-    public static final int[] S1 = {
+    public static final short[] S1 = {
         0x55,0xc2,0x63,0x71,0x3b,0xc8,0x47,0x86,0x9f,0x3c,0xda,0x5b,0x29,0xaa,0xfd,0x77,
         0x8c,0xc5,0x94,0x0c,0xa6,0x1a,0x13,0x00,0xe3,0xa8,0x16,0x72,0x40,0xf9,0xf8,0x42,
         0x44,0x26,0x68,0x96,0x81,0xd9,0x45,0x3e,0x10,0x76,0xc6,0xa7,0x8b,0x39,0x43,0xe1,
@@ -50,7 +50,7 @@ public final class Zuc256Tables {
     /**
      * 常量数组 D
      */
-    public static final int[][] ZUC256_D = {
+    public static final short[][] ZUC256_D = {
         {0x22,0x2F,0x24,0x2A,0x6D,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x52,0x10,0x30},
         {0x22,0x2F,0x25,0x2A,0x6D,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x52,0x10,0x30},
         {0x23,0x2F,0x24,0x2A,0x6D,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x52,0x10,0x30},
diff --git a/Project/Src/com/cscn/Zuc256Util.java b/Project/Src/com/cscn/Zuc256Util.java
index cbfb5f1..f45201f 100644
--- a/Project/Src/com/cscn/Zuc256Util.java
+++ b/Project/Src/com/cscn/Zuc256Util.java
@@ -7,22 +7,36 @@ public final class Zuc256Util {
 
     private Zuc256Util() {}
 
-    /** 辅助方法：将字节数组转换为32位整数 */
-    public static int getU32(byte[] p, int offset) {
-        return ((p[offset] & 0xFF) << 24) |
-                ((p[offset + 1] & 0xFF) << 16) |
-                ((p[offset + 2] & 0xFF) << 8) |
-                (p[offset + 3] & 0xFF);
+    /** 辅助方法：从字节数组取出 32 位整数，存放到 short[2] (lo, hi) */
+    public static void getU32(byte[] p, short offset, short[] out32 /* len=2 */) {
+        out32[0] = (short) (((p[offset + 2] & 0xFF) << 8) | (p[offset + 3] & 0xFF)); //低16位
+        out32[1] = (short) (((p[offset] & 0xFF) << 8) | (p[offset + 1] & 0xFF)); //高16位
     }
 
-    /** 辅助方法：将32位整数转换为字节数组 */
-    public static void putU32(byte[] p, int offset, int v) {
-        p[offset] = (byte) (v >> 24);
-        p[offset + 1] = (byte) (v >> 16);
-        p[offset + 2] = (byte) (v >> 8);
-        p[offset + 3] = (byte) v;
+
+//    /** 辅助方法：将32位整数转换为字节数组 */
+//    public static void putU32(byte[] p, int offset, int v) {
+//        p[offset] = (byte) (v >> 24);
+//        p[offset + 1] = (byte) (v >> 16);
+//        p[offset + 2] = (byte) (v >> 8);
+//        p[offset + 3] = (byte) v;
+//    }
+
+    /** 辅助方法：将32位整数(vlo=低16位, vhi=高16位)写入字节数组 */
+    public static void putU32(byte[] p, short offset, short vlo, short vhi) {
+        // 写高16位
+        putU16(p, offset, vhi);
+        // 写低16位
+        putU16(p, (short)(offset + 2), vlo);
     }
 
+    /** 辅助方法：将16位整数(short)写入字节数组，高字节在前 */
+    public static void putU16(byte[] p, short offset, short v) {
+        p[offset]     = (byte) ((v >> 8) & 0xFF);
+        p[offset + 1] = (byte) (v & 0xFF);
+    }
+
+
     // === 31/32 位运算 ===
 
     /** 31位加法 */