If you've updated your device to iOS 7.1.x, you might have noticed that the Lock screen keyboard looks quite different than the default keyboard that pops up when you're typing. The new keyboard appears only on the Lock screen when you're entering an alphanumeric passcode, and it is not available for other parts of iOS 7.1. A new tweak appropriately called LockKeyboard allows you to bring the iOS 7.1 Lock screen keyboard to your entire device.
LockKeyboard lets you use the iOS 7.1 Lock screen keyboard across iOS