diff -r 8ac9ac8d9143 -r 48a010b35af2 cubicweb/crypto.py
--- a/cubicweb/crypto.py	Thu May 16 04:42:59 2019 +0200
+++ b/cubicweb/crypto.py	Tue May 21 10:18:38 2019 +0200
@@ -26,6 +26,8 @@
 
 _CYPHERERS = {}
 def _cypherer(seed):
+    if isinstance(seed, str):
+        seed = seed.encode('utf-8')
     try:
         return _CYPHERERS[seed]
     except KeyError: