def index(request):
    if request.method == 'POST':
        form = LoginForm(request.POST)
        if form.is_valid():
            cd = form.cleaned_data
            user = Users.objects.get(login = cd.get('login'), password = cd.get('password'))
            rights = UserGroupRighs.objects.filter(group = user.group)
            request.session['login'] = user
            request.session['user_rights'] = rights
            return redirect(start)

 SESSION_ENGINE = 'django.contrib.sessions.backends.cache'
MIDDLEWARE_CLASSES	= [
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware']
INSTALLED_APPS = 	(...
    'django.contrib.sessions',
 ...)