Try writing your own SessionBackend, which inherits from the existing one and overrides the method cycle_key.
1 V settings.py:
SESSION_ENGINE = 'my_app.session_backend'
2 my_app.session_backend.py:
from django.contrib.sessions.backends.db import SessionStore as DbSessionStore
class SessionStore(DbSessionStore):
def cycle_key(self):
pass
cycle_key login .
, ;)