not store tokens, just the hashes

utils.py

@@ -5,6 +5,7 @@ import os
 from werkzeug.utils import secure_filename
 import html
 import sqlite3
+import hashlib
 
 def connect_db():
     return sqlite3.connect(app.config['DATABASE'])
@@ -32,7 +33,8 @@ def create_db(db_file):
     )
     db.commit()
 
-
+def get_hash(s):
+    return hashlib.sha224(s.encode('utf-8')).hexdigest()
 
 def get_token_counts(db, key):
     cur = db.cursor()
@@ -92,7 +94,7 @@ def has_voted(key, token):
     cur.execute(
         "SELECT token FROM tokens WHERE token = ? AND answered = 'true' AND question_set = ?",
         (
-            token,
+            get_hash(token),
             key
         )
     )
@@ -245,7 +247,7 @@ def write_vote(key, token, answers, form):
         cur.execute(
             "UPDATE tokens SET answered = 'true' WHERE token = ? AND question_set = ?",
             (
-                token,
+                get_hash(token),
                 key
             )
         )