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two-factor_authentication [2019/08/21 07:37]
neil
two-factor_authentication [2021/07/06 10:26] (current)
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 ====Key points ==== ====Key points ====
   * [[two-factor_authentication#"Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know|"Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know]]   * [[two-factor_authentication#"Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know|"Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know]]
 +  * [[two-factor_authentication#Enable two-factor authentication wherever you can|Enable two-factor authentication wherever you can]]
 +  * [[two-factor_authentication#Have a back-up mechanism in case you lose your device(s)|Have a back-up mechanism in case you lose your device(s)]]
 +  * [[two-factor_authentication#Something you have: one-time codes|Something you have: one-time codes]]
  
 ===="Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know==== ===="Two-factor authentication" means using something you are, or something you have, to log in to a site, rather than just something you know====
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 Because of the security benefits of having two-factor authentication in place, you should enable it wherever you can. This normally means "on every site and service which supports it". Because of the security benefits of having two-factor authentication in place, you should enable it wherever you can. This normally means "on every site and service which supports it".
 +
 +Check first that you can use whatever two-factor approach you are using on whatever devices you tend to use. If you primarily use your phone, and the service requires a hardware device which is incompatible with your phone, you'll be causing yourself a lot of inconvenience, which may overreach the security benefit.
 +
 +Some password managers will suggest logins for which two-factor authentication is available. There's also a good list [[https://www.telesign.com/turnon2fa/tutorials/|here]].
  
 ====Have a back-up mechanism in case you lose your device(s)==== ====Have a back-up mechanism in case you lose your device(s)====
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 These one-time codes are usually generated by a piece of software on your computer or phone, or else through a dedicated hardware device. These one-time codes are usually generated by a piece of software on your computer or phone, or else through a dedicated hardware device.
  
-Backup codes.+===Time-based One-Time Passwords (TOTP) are common and easy to use===ย 
 +ย 
 +Lots of sites support one-time codes, which changes after a few seconds. This is known as "TOTP" or "time-based one-time passwords".ย 
 +ย 
 +Once set up, you need to log in using your username and password, and then put in the current code before it expires. This means that you always need to have the mechanism to generate the code to hand, when you want to log in.ย 
 +ย 
 +These work by generating a special code, which you store on a device, and which the service stores. So, to use TOTP, you need a means of storing this special code. (You may not even see the special code; you may just need to scan a QR code, which automates the storage, so that you see only the effect of it, which is the generation of six-digit one-time passwords, which change routinely).ย 
 +ย 
 +You might be able to use [[passwords#Use a password manager|password manager]] to store your codes, along with your site login, if you are comfortable storing everything in one place.
  
-Two hardware devicesso you can store backup safely in safe.+Alternatively, you can use dedicated app, such as "Google Authenticator".
  
 +You might also use a hardware device.
  
 +===Avoid text message for delivery of codes ===
  
 +Some services offer the real-time delivery of one-time codes using text message. If possible, avoid this, in favour of an approach which doesn't use text messages.
  
-Option of 2FA โ€” so if you do make mistake and give away your username and password, still hard for someone to make use of them, as they require an extra piece of data which (hopefully) on your can generate+First, text messages are not secure, and sufficiently motivated attacker is likely to be able to access your messages.
  
-Downside of 2FA is that, if you lose your device, you may well be locked out of your accounts+Second, if someone manages to hijack your phone number (sometimes known as "SIM swapping")they get all your messages and calls. Irritating at the best of times, but even more problematic if you rely on text messaging to log in to your services โ€” the double whammy of you not being able to log in until you get it fixed, and someone else getting your codes.
  
-If the second code is delivered over SMS, you can probably get a new SIM, get your provider to move your number across to the new SIMand you are up and running+Thirdif you are out of signalyou cannot get your code โ€” no good for places with Internet connectivitybut no or poor cellular service.
  
-If you use an app โ€” which means you are not reliant on getting an SMS โ€” you may struggle more. I donโ€™t have a great solution for this at the moment. 
  
 ====Hardware security tokens ==== ====Hardware security tokens ====
 {{::img_0417.jpg?400|}} {{::img_0417.jpg?400|}}
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two-factor_authentication.1566369476.txt.gz ยท Last modified: 2021/07/06 10:26 (external edit)