It lives in your head and is ideally known only to you. Something you know is typically a password. That doesn't mean a second password, but at least any two from a list of three possible factors: Multi-factor authentication, sometimes called two-factor authentication or 2FA, seeks to change that by using more than one authentication factor. For another, people tend to reuse passwords, meaning that if one account is compromised, all the other accounts with the same password are also at risk. For one thing, we're bad at remembering them and even worse at picking unique, complex passwords that can stand up to attacks. The authentication method most of us are familiar with is being required to enter a username and password. How to Set Up Two-Factor Authenticationīuying Guide: The Best Security Keys for Multi-Factor Authentication.How to Record the Screen on Your Windows PC or Mac.How to Convert YouTube Videos to MP3 Files.

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