To continue reading this story, enter your password now. If you do not have a password, please create one. It must contain a minimum of eight characters, including upper- and lower-case letters and one number. This is for your own good. Nonsense, of course, but it helps illustrate a point: You will need a computer password today, maybe a half dozen or more — those secret sign-ins that serve as sentries for everything from Amazon shopping carts to work files to online bank accounts. Just when you have them all sorted out, along comes another “urgent” directive from the bank...