diff --git a/gptc/tokenizer.py b/gptc/tokenizer.py
index 8915682..c2725f6 100644
--- a/gptc/tokenizer.py
+++ b/gptc/tokenizer.py
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 from typing import List, Union
+import hashlib
+import base64
 
 try:
     import emoji
@@ -41,10 +43,16 @@ def tokenize(
     tokens = [string for string in tokens if string]
 
     if max_ngram_length == 1:
-        return tokens
+        ngrams = tokens
     else:
         ngrams = []
         for ngram_length in range(1, max_ngram_length + 1):
             for index in range(len(tokens) + 1 - ngram_length):
                 ngrams.append(" ".join(tokens[index : index + ngram_length]))
-        return ngrams
+
+    return [
+        base64.b64encode(
+            hashlib.sha256(token.encode("utf-8")).digest()[:6]
+        ).decode("ascii")
+        for token in ngrams
+    ]