Amazon has quietly rolled out support for two-factor authentication, allowing shoppers to add an extra layer of security to their accounts. The move couldn't have come at a better time - just ahead of the holiday shopping season - although it's a bit puzzling as to why it was done in secret.

Engadget's Richard Lawler first noticed the option for two-factor authentication, sometimes referred to as two-step verification, during a routine password change session (which by the way, isn't a bad idea at all). Lawler said an Amazon engineer told him the feature launched a couple of weeks ago following a private beta.

Nevertheless, the option is now available and it'd be a wise idea to enable it. To do so, simply head to your Amazon account settings page and look for Advanced Security Settings.

For those new to two-factor authentication, it's essentially exactly what it sounds like. Logging into a site or service with the added layer of protection requires a password as well as an additional security code, typically sent to your smartphone in the form of a text message, through an automated voice call or via an app like Google Authenticator.

Two-factor authentication is one of the best methods we currently have to combat the risk of unauthorized account access. It is a compromise, however, as you're essentially sacrificing convenience for the sake of security. Amazon notes in its FAQ that you can set it up in a way that it won't ask for a security code when signing in on computers and devices you routinely use. After the first login, you'll only need to enter your password as usual to access your account.

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