diff --git a/shadowsocks/obfsplugin/auth_chain.py b/shadowsocks/obfsplugin/auth_chain.py
index f796fd1..d9d3326 100644
--- a/shadowsocks/obfsplugin/auth_chain.py
+++ b/shadowsocks/obfsplugin/auth_chain.py
@@ -56,11 +56,16 @@ def create_auth_chain_d(method):
     return auth_chain_d(method)
 
 
+def create_auth_chain_e(method):
+    return auth_chain_e(method)
+
+
 obfs_map = {
     'auth_chain_a': (create_auth_chain_a,),
     'auth_chain_b': (create_auth_chain_b,),
     'auth_chain_c': (create_auth_chain_c,),
     'auth_chain_d': (create_auth_chain_d,),
+    'auth_chain_e': (create_auth_chain_e,),
 }
 
 
@@ -836,3 +841,20 @@ class auth_chain_d(auth_chain_b):
         # random select a size in the leftover data_size_list0
         final_pos = pos + random.next() % (len(self.data_size_list0) - pos)
         return self.data_size_list0[final_pos] - other_data_size
+
+
+class auth_chain_e(auth_chain_d):
+    def __init__(self, method):
+        super(auth_chain_d, self).__init__(method)
+        self.salt = b"auth_chain_e"
+        self.no_compatible_method = 'auth_chain_e'
+
+    def rnd_data_len(self, buf_size, last_hash, random):
+        other_data_size = buf_size + self.server_info.overhead
+        # if other_data_size > the bigest item in data_size_list0, not padding any data
+        if other_data_size >= self.data_size_list0[-1]:
+            return 0
+
+        # use the mini size in the data_size_list0
+        pos = bisect.bisect_left(self.data_size_list0, other_data_size)
+        return self.data_size_list0[pos] - other_data_size