diff --git a/kaitaistruct.py b/kaitaistruct.py
index ba23713..8290c86 100644
--- a/kaitaistruct.py
+++ b/kaitaistruct.py
@@ -217,23 +217,11 @@ def read_strz(self, encoding, term, include_term, consume_term, eos_error):
 
     @staticmethod
     def process_xor_one(data, key):
-        r = bytearray(data)
-        for i in range(len(r)):
-            r[i] ^= key
-        return bytes(r)
+        return bytes(bytearray(v ^ key for v in bytearray(data)))
 
     @staticmethod
     def process_xor_many(data, key):
-        r = bytearray(data)
-        k = bytearray(key)
-        ki = 0
-        kl = len(k)
-        for i in range(len(r)):
-            r[i] ^= k[ki]
-            ki += 1
-            if ki >= kl:
-                ki = 0
-        return bytes(r)
+        return bytes(bytearray(a ^ b for a, b in map(bytearray, zip(data, key))))
 
     @staticmethod
     def process_rotate_left(data, amount, group_size):