Keep this to yourself, obviously, but answer honestly: How many different passwords do you use at one time? And, how difficult would it be for someone to guess any of them?
The venerable username-password combination has been around for as long as there have been individual computer user accounts—dating back to the punch-card era. Although we have tried various ways to make them more secure—requiring a mixture of upper- and lowercase letters, numbers, and special characters or requiring passwords to be changed periodically—the fact remains that the only passwords that are truly secure (that is, difficult to guess) are impossible to remember.
It’s time to rethink user authentication, and some very smart people are doing just that.