typo--

Author: Fabien Coelho

Diff for: docs/REFERENCE.md

@@ -87,7 +87,7 @@ with the _secret_ only:
 - values are encrypted depending on the actual key value, thus cannot be
   recovered without the key.
 
-Hashing is based on _SHA3_, encryption uses on _Salsa20_.
+Hashing is based on _SHA3_, encryption uses _Salsa20_.
 
 ```python
 cache = EncryptedCache(actual_cache, secret=b"super secret stuff you cannot guess", hsize=16)