diff --git a/assets/shadowsocks b/assets/shadowsocks
index c7f2e590..507b7dff 100755
Binary files a/assets/shadowsocks and b/assets/shadowsocks differ
diff --git a/jni/shadowsocks/encrypt.c b/jni/shadowsocks/encrypt.c
index e31384c5..379b42ab 100755
--- a/jni/shadowsocks/encrypt.c
+++ b/jni/shadowsocks/encrypt.c
@@ -1,9 +1,6 @@
 #include "encrypt.h"
 #include "android.h"
 
-#include <openssl/md5.h>
-#include <endian.h>
-
 static int random_compare(const void *_x, const void *_y) {
     uint32_t i = _i;
     uint64_t a = _a;
@@ -115,30 +112,42 @@ static void mergesort(uint8_t array[], int length)
 }
 
 void encrypt(char *buf, int len) {
-    char *end = buf + len;
-    while (buf < end) {
-        *buf = (char)encrypt_table[(uint8_t)*buf];
-        buf++;
+    if (_method == RC4_ENC) {
+        unsigned char mybuf[BUF_SIZE];
+        RC4(&rc4_key, len, (unsigned char *) buf, mybuf);
+        memcpy(buf, mybuf, len);
+    } else {
+        char *end = buf + len;
+        while (buf < end) {
+            *buf = (char)encrypt_table[(uint8_t)*buf];
+            buf++;
+        }
     }
 }
 
 void decrypt(char *buf, int len) {
-    char *end = buf + len;
-    while (buf < end) {
-        *buf = (char)decrypt_table[(uint8_t)*buf];
-        buf++;
+    if (_method == RC4_ENC) {
+        unsigned char mybuf[BUF_SIZE];
+        RC4(&rc4_key, len, (unsigned char *) buf, mybuf);
+        memcpy(buf, mybuf, len);
+    } else {
+        char *end = buf + len;
+        while (buf < end) {
+            *buf = (char)decrypt_table[(uint8_t)*buf];
+            buf++;
+        }
     }
 }
 
 int send_encrypt(int sock, char *buf, int len, int flags) {
-    char mybuf[4096];
+    char mybuf[BUF_SIZE];
     memcpy(mybuf, buf, len);
     encrypt(mybuf, len);
     return send(sock, mybuf, len, flags);
 }
 
 int recv_decrypt(int sock, char *buf, int len, int flags) {
-    char mybuf[4096];
+    char mybuf[BUF_SIZE];
     int result = recv(sock, mybuf, len, flags);
     memcpy(buf, mybuf, len);
     decrypt(buf, len);
@@ -146,20 +155,24 @@ int recv_decrypt(int sock, char *buf, int len, int flags) {
 }
 
 void get_table(const char* key) {
-    uint8_t *table = encrypt_table;
-    uint8_t *tmp_hash = MD5((const uint8_t*)key, strlen(key), NULL);
-    _a = htole64(*(uint64_t *)tmp_hash);
-    uint32_t i;
+    if (_method == RC4_ENC) {
+        RC4_set_key(&rc4_key, strlen(key), (unsigned char *) key);
+    } else {
+        uint8_t *table = encrypt_table;
+        uint8_t *tmp_hash = MD5((const uint8_t*)key, strlen(key), NULL);
+        _a = htole64(*(uint64_t *)tmp_hash);
+        uint32_t i;
 
-    for(i = 0; i < 256; ++i) {
-        table[i] = i;
-    }
-    for(i = 1; i < 1024; ++i) {
-        _i = i;
-        mergesort(table, 256);
-    }
-    for(i = 0; i < 256; ++i) {
-        // gen decrypt table from encrypt table
-        decrypt_table[encrypt_table[i]] = i;
+        for(i = 0; i < 256; ++i) {
+            table[i] = i;
+        }
+        for(i = 1; i < 1024; ++i) {
+            _i = i;
+            mergesort(table, 256);
+        }
+        for(i = 0; i < 256; ++i) {
+            // gen decrypt table from encrypt table
+            decrypt_table[encrypt_table[i]] = i;
+        }
     }
 }
diff --git a/jni/shadowsocks/encrypt.h b/jni/shadowsocks/encrypt.h
index 700398d1..eb2ee1ff 100755
--- a/jni/shadowsocks/encrypt.h
+++ b/jni/shadowsocks/encrypt.h
@@ -4,9 +4,19 @@
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <openssl/md5.h>
+#include <openssl/rc4.h>
+#include <endian.h>
+
+#define BUF_SIZE 4096
+
+#define TABLE_ENC 0
+#define RC4_ENC   1
 
 unsigned char encrypt_table[256];
 unsigned char decrypt_table[256];
+RC4_KEY rc4_key;
+
 void get_table(const char* key);
 void encrypt(char *buf, int len);
 void decrypt(char *buf, int len);
@@ -15,4 +25,5 @@ int recv_decrypt(int sock, char *buf, int len, int flags);
 
 unsigned int _i;
 unsigned long long _a;
+int _method;
 
diff --git a/jni/shadowsocks/local.c b/jni/shadowsocks/local.c
index 36f22150..d523273b 100644
--- a/jni/shadowsocks/local.c
+++ b/jni/shadowsocks/local.c
@@ -21,7 +21,6 @@
 
 #include "local.h"
 #include "socks5.h"
-#include "encrypt.h"
 #include "android.h"
 
 #define min(a,b) (((a)<(b))?(a):(b))
@@ -567,12 +566,13 @@ int main (int argc, char **argv)
     char *port = NULL;
     char *key = NULL;
     char* timeout = "10";
+    char* method = NULL;
     int c;
     int f_flags = 0;
 
     opterr = 0;
 
-    while ((c = getopt (argc, argv, "fs:p:l:k:t:")) != -1) {
+    while ((c = getopt (argc, argv, "fs:p:l:k:t:m:")) != -1) {
         switch (c) {
             case 's':
                 server = optarg;
@@ -592,6 +592,9 @@ int main (int argc, char **argv)
             case 't':
                 timeout = optarg;
                 break;
+            case 'm':
+                method = optarg;
+                break;
         }
     }
 
@@ -600,6 +603,12 @@ int main (int argc, char **argv)
         exit(EXIT_FAILURE);
     }
 
+    if (method != NULL) {
+        if (strcmp(method, "rc4") == 0) {
+            _method = RC4_ENC;
+        }
+    }
+
     if (f_flags) {
 
         /* Our process ID and Session ID */
@@ -653,7 +662,7 @@ int main (int argc, char **argv)
     _remote_port = strdup(remote_port);
     _timeout = atoi(timeout);
 
-    LOGD("calculating ciphers");
+    LOGD("calculating ciphers %d", _method);
     get_table(key);
 
     int listenfd;
diff --git a/jni/shadowsocks/local.h b/jni/shadowsocks/local.h
index db8042fc..60a94e6e 100644
--- a/jni/shadowsocks/local.h
+++ b/jni/shadowsocks/local.h
@@ -2,7 +2,7 @@
 
 #include <ev.h>
 
-#define BUF_SIZE 4096
+#include "encrypt.h"
 
 struct listen_ctx {
 	ev_io io;
diff --git a/libs/armeabi/shadowsocks b/libs/armeabi/shadowsocks
index c7f2e590..507b7dff 100755
Binary files a/libs/armeabi/shadowsocks and b/libs/armeabi/shadowsocks differ
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 95702f0c..afead46d 100755
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -61,10 +61,15 @@
     <string name="copy_rights">Shadowsocks is an open source socks proxy.\n\nYou can find more details here:\ngithub.com/shadowsocks
     </string>
     <string name="about">About</string>
-    <string name="proxy_type">Proxy Type</string>
-    <array name="proxy_type_entry">
-        <item>GAE</item>
-        <item>PaaS</item>
+
+    <string name="enc_method">Encrypt Method</string>
+    <array name="enc_method_entry">
+        <item>Table</item>
+        <item>RC4</item>
+    </array>
+    <array name="enc_method_value">
+        <item>table</item>
+        <item>rc4</item>
     </array>
 
     <string-array name="gfw_list">
diff --git a/res/xml/shadowsocks_preference.xml b/res/xml/shadowsocks_preference.xml
index 9701c28b..3b026e80 100755
--- a/res/xml/shadowsocks_preference.xml
+++ b/res/xml/shadowsocks_preference.xml
@@ -39,6 +39,14 @@
                 android:summary="@string/sitekey_summary"
                 android:title="@string/sitekey">
         </EditTextPreference>
+        <ListPreference
+                android:dependency="isRunning"
+                android:defaultValue="table"
+                android:key="encMethod"
+                android:entries="@array/enc_method_entry"
+                android:entryValues="@array/enc_method_value"
+                android:title="@string/enc_method">
+        </ListPreference>
     </PreferenceCategory>
     <PreferenceCategory android:title="@string/fearute_cat">
         <CheckBoxPreference
diff --git a/src/com/github/shadowsocks/Shadowsocks.java b/src/com/github/shadowsocks/Shadowsocks.java
index 3e6a8dd3..adfd3921 100755
--- a/src/com/github/shadowsocks/Shadowsocks.java
+++ b/src/com/github/shadowsocks/Shadowsocks.java
@@ -98,6 +98,7 @@ public class Shadowsocks extends PreferenceActivity implements
     private EditTextPreference portText;
     private EditTextPreference remotePortText;
     private EditTextPreference sitekeyText;
+    private ListPreference encMethodText;
     private Preference proxyedApps;
     private CheckBoxPreference isBypassAppsCheck;
     private CheckBoxPreference isRunningCheck;
@@ -169,6 +170,7 @@ public class Shadowsocks extends PreferenceActivity implements
         portText = (EditTextPreference) findPreference("port");
         remotePortText = (EditTextPreference) findPreference("remotePort");
         sitekeyText = (EditTextPreference) findPreference("sitekey");
+        encMethodText = (ListPreference) findPreference("encMethod");
         proxyedApps = findPreference("proxyedApps");
 
         isBypassAppsCheck = (CheckBoxPreference) findPreference("isBypassApps");
@@ -343,6 +345,9 @@ public class Shadowsocks extends PreferenceActivity implements
         if (!settings.getString("sitekey", "").equals(""))
             sitekeyText.setSummary(settings.getString("sitekey", ""));
 
+        if (!settings.getString("encMethod", "").equals(""))
+            encMethodText.setSummary(settings.getString("encMethod", ""));
+
         if (!settings.getString("port", "").equals(""))
             portText.setSummary(settings.getString("port",
                     getString(R.string.port_summary)));
@@ -416,6 +421,9 @@ public class Shadowsocks extends PreferenceActivity implements
                 sitekeyText.setSummary(getString(R.string.sitekey_summary));
             else
                 sitekeyText.setSummary(settings.getString("sitekey", ""));
+        else if (key.equals("encMethod"))
+            if (!settings.getString("encMethod", "").equals(""))
+                encMethodText.setSummary(settings.getString("encMethod", ""));
         else if (key.equals("proxy"))
             if (settings.getString("proxy", "").equals("")) {
                 proxyText.setSummary(getString(R.string.proxy_summary));
diff --git a/src/com/github/shadowsocks/ShadowsocksService.java b/src/com/github/shadowsocks/ShadowsocksService.java
index 3eadc403..0a8abc4f 100755
--- a/src/com/github/shadowsocks/ShadowsocksService.java
+++ b/src/com/github/shadowsocks/ShadowsocksService.java
@@ -164,6 +164,7 @@ public class ShadowsocksService extends Service {
     private boolean isGFWList = false;
     private boolean isBypassApps = false;
     private boolean isDNSProxy = false;
+    private String encMethod;
     private ProxyedApp apps[];
     private Method mSetForeground;
     private Method mStartForeground;
@@ -205,8 +206,8 @@ public class ShadowsocksService extends Service {
             @Override
             public void run() {
                 final String cmd = String.format(BASE +
-                        "shadowsocks -s \"%s\" -p \"%d\" -l \"%d\" -k \"%s\"",
-                        appHost, remotePort, port, sitekey);
+                        "shadowsocks -s \"%s\" -p \"%d\" -l \"%d\" -k \"%s\" -m \"%s\"",
+                        appHost, remotePort, port, sitekey, encMethod);
                 Node.exec(cmd);
             }
         }.start();
@@ -238,6 +239,7 @@ public class ShadowsocksService extends Service {
 
         appHost = settings.getString("proxy", "127.0.0.1");
         sitekey = settings.getString("sitekey", "default");
+        encMethod = settings.getString("encMethod", "table");
         try {
             remotePort = Integer.valueOf(settings.getString("remotePort", "1984"));
         } catch (NumberFormatException ex) {