diff --git a/libs/sm/blktap2.py b/libs/sm/blktap2.py
index edea11a22..75fd44544 100644
--- a/libs/sm/blktap2.py
+++ b/libs/sm/blktap2.py
@@ -29,6 +29,7 @@
 import syslog as _syslog
 import glob
 import json
+import base64
 from syslog import openlog, syslog
 from stat import *  # S_ISBLK(), ...
 
@@ -379,8 +380,7 @@ def open(cls, pid, minor, _type, _file, options):
 
             if not key:
                 raise util.SMException("No key found with key hash {}".format(key_hash))
-            input = key
-            text_mode = False
+            input = base64.b64encode(key).decode('utf-8')
             args.append('-E')
 
         cls._pread(args=args, input=input, text_mode=text_mode)
diff --git a/libs/sm/cbtutil.py b/libs/sm/cbtutil.py
index 8b0aa4c75..f4dceef80 100644
--- a/libs/sm/cbtutil.py
+++ b/libs/sm/cbtutil.py
@@ -19,6 +19,7 @@
 
 from sm.core import util
 import uuid
+import base64
 from sm.constants import CBT_UTIL
 
 
@@ -81,10 +82,10 @@ def get_cbt_consistency(file_name):
 
 def get_cbt_bitmap(file_name):
     """Get bitmap field from log file"""
-    cmd = [CBT_UTIL, "get", "-n", file_name, "-b"]
-    ret = _call_cbt_util(cmd, text=False)
-    # Do not strip the return string. It's a byte string and stripping
-    # it sometimes leads to loss of information
+    cmd = [CBT_UTIL, "get", "-n", file_name, "-b", "-E"]
+    ret = _call_cbt_util(cmd)
+    if ret is not None:
+        ret = base64.b64decode(ret.strip())
     return ret
 
 
diff --git a/libs/sm/vhdutil.py b/libs/sm/vhdutil.py
index ccb5e57b4..1f6eb3253 100644
--- a/libs/sm/vhdutil.py
+++ b/libs/sm/vhdutil.py
@@ -21,6 +21,7 @@
 import errno
 import zlib
 import re
+import base64
 from sm.core import xs_errors
 import time
 
@@ -298,8 +299,10 @@ def getDepth(path):
 
 
 def getBlockBitmap(path):
-    cmd = [VHD_UTIL, "read", OPT_LOG_ERR, "-B", "-n", path]
-    text = ioretry(cmd, text=False)
+    cmd = [VHD_UTIL, "read", OPT_LOG_ERR, "-B", "-n", path, "-E"]
+    text = ioretry(cmd)
+    if text is not None:
+        text = base64.b64decode(text.strip())
     return zlib.compress(text)
 
 
diff --git a/tests/test_cbt.py b/tests/test_cbt.py
index 865f74f2e..3121602c7 100644
--- a/tests/test_cbt.py
+++ b/tests/test_cbt.py
@@ -764,7 +764,8 @@ def test_list_changed_blocks_strip_sensitive_bitmap(self, context, mock_lock,
         data = b'\x0c\xbb3a\xf75Jy\x17\x04\x92;\x0b\x93\xf3E'
         bitmap2.frombytes(data)
         mock_size.side_effect = [vdi_size1, vdi_size2]
-        mock_call.side_effect = [bitmap1.tobytes(), data]
+        mock_call.side_effect = [base64.b64encode(bitmap1.tobytes()).decode(),
+                                base64.b64encode(data).decode()]
         bitmap1.bytereverse()
         bitmap2.bytereverse()
         expected_string = base64.b64encode((bitmap1 | bitmap2).tobytes()).decode()
diff --git a/tests/test_vhdutil.py b/tests/test_vhdutil.py
index 0af601397..245316a75 100644
--- a/tests/test_vhdutil.py
+++ b/tests/test_vhdutil.py
@@ -2,6 +2,7 @@
 import unittest
 import unittest.mock as mock
 import zlib
+import base64
 
 from sm import lvhdutil
 from sm import vhdutil
@@ -147,8 +148,8 @@ def test_get_block_bitmap(self, context):
         def test_function(args, inp):
             nonlocal call_args
             call_args = args
-            # Not a real bitmap data
-            return 0, b"some dummy text", b""
+            # Since vhd-util now returns base64 encoded data with -E flag
+            return 0, base64.b64encode(b"some dummy text"), b""
 
         context.add_executable(VHD_UTIL, test_function)
 
@@ -160,7 +161,7 @@ def test_function(args, inp):
         self.assertEqual("some dummy text", zlib.decompress(result).decode())
         self.assertEqual([
             VHD_UTIL, "read", "--debug", "-B",
-            "-n", TEST_VHD_NAME],
+            "-n", TEST_VHD_NAME, "-E"],
             call_args)
 
     @testlib.with_context