Wednesday, February 29, 2012

Google two phase authentication

It sounds like such a good idea.  When you log on to a new device they send you a text with a verification code.  Great!  It makes sure that only the person with the mobile can get into your google account.

One thing I didn't understand - How do I get rid of the cookie on a public PC.  I didn't see a question on the login page!

Unfortunately the downsides out way the security advantage.

Minor downside.
I'm in the habit of clearing the browser store - cache, cookies, etc., so that means I get a text.  On the screen it says enter the verification code ending in 20.  None of the six digits in the text message are either 2 or 0.  The code worked, or I wouldn't be blogging now!

Major downside.
For applications that don't have cookies - in my case thunderbird - there are application passwords "that you should only have to enter once".  I keep my passwords in my brain.  I do not let applications remember them.  That I consider the safer option.  I cannot remember 16 random characters, I would have to write it down - defeating the whole point of passwords in the first place.

Password security.
It is each applications responsibility to make the password that a user chooses safe.  Strong passwords are a con.  A password cracker that simple tries letters until it gets logged on will still get there and quickly even with a 16 character password.  Password crackers can be delayed.  The application simply waits 1 second before telling the user their password is wrong.  2 seconds next time, 4 after that - and so on.  The user will hardly notice the delay for a simple miss-key.  The password cracker can now only try 6 passwords in the first minute.

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