Secret-Lock cydia tweak keeps your lockscreen FROZEN until your secret gesture (handled by activator) is triggered.
The idea is to keep strangers outside your device without the need to setup a password or without worrying to keep secret your passcode.
Notifications will be visible, but as long as the lock is active, they can’t be opened.
Control center and notification center are disabled as is the camera grabber.
I suggest to setup multiple events to unlock your device, just to be sure not to be locked out.