Ideal for larger screens used by later models of smartphone or tablet, a third means of verification uses multiple galleries in a single display. This in turn means access is provided with a 'lock-screen' like conventional key-pads, but more secure.

Working from left to right and top to bottom through those eight tic-tac-toe arrangements of faces seen here, the 8-digit passcode '18945459' is entered without you ever needing to recall the sequence.

Those faces featured are US presidents but would otherwise be your friends, colleagues or family members.

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