diff --git a/src/helper_ackPayload.py b/src/helper_ackPayload.py
index ef99ec2a..bd595324 100644
--- a/src/helper_ackPayload.py
+++ b/src/helper_ackPayload.py
@@ -1,31 +1,32 @@
-import hashlib
 import highlevelcrypto
-import random
 import helper_random
-from binascii import hexlify, unhexlify
-from struct import pack, unpack
+from binascii import hexlify
+from struct import pack
 from addresses import encodeVarint
 
 # This function generates payload objects for message acknowledgements
-# Several stealth levels are available depending on the privacy needs; 
+# Several stealth levels are available depending on the privacy needs;
 # a higher level means better stealth, but also higher cost (size+POW)
 #   - level 0: a random 32-byte sequence with a message header appended
 #   - level 1: a getpubkey request for a (random) dummy key hash
 #   - level 2: a standard message, encrypted to a random pubkey
 
+
 def genAckPayload(streamNumber=1, stealthLevel=0):
-    if (stealthLevel==2):      # Generate privacy-enhanced payload
+    if (stealthLevel == 2):      # Generate privacy-enhanced payload
         # Generate a dummy privkey and derive the pubkey
-        dummyPubKeyHex = highlevelcrypto.privToPub(hexlify(helper_random.randomBytes(32)))
+        dummyPubKeyHex = highlevelcrypto.privToPub(
+            hexlify(helper_random.randomBytes(32)))
         # Generate a dummy message of random length
         # (the smallest possible standard-formatted message is 234 bytes)
-        dummyMessage = helper_random.randomBytes(random.randint(234, 800))
+        dummyMessage = helper_random.randomBytes(
+            helper_random.randomrandrange(234, 801))
         # Encrypt the message using standard BM encryption (ECIES)
         ackdata = highlevelcrypto.encrypt(dummyMessage, dummyPubKeyHex)
         acktype = 2  # message
         version = 1
 
-    elif (stealthLevel==1):    # Basic privacy payload (random getpubkey)
+    elif (stealthLevel == 1):    # Basic privacy payload (random getpubkey)
         ackdata = helper_random.randomBytes(32)
         acktype = 0  # getpubkey
         version = 4
@@ -35,6 +36,7 @@ def genAckPayload(streamNumber=1, stealthLevel=0):
         acktype = 2  # message
         version = 1
 
-    ackobject = pack('>I', acktype) + encodeVarint(version) + encodeVarint(streamNumber) + ackdata
+    ackobject = pack('>I', acktype) + encodeVarint(
+        version) + encodeVarint(streamNumber) + ackdata
 
     return ackobject