Google 2-step verification – a usability note

Google’s two-factor authentication system (they call it “2-step verification“) is a good safeguard against online criminals hijacking your account.*

After enabling 2-step verification, whenever you login to your Google account (e.g. for Gmail) you get a text message on your phone. Unless you provide the numeric code of that text message to Google, you cannot access your account.

This is classic two-factor authentication in that it ensures

  1. You know the password for your account and
  2. You have your phone in your possession

As this would quickly get annoying for people who login/out of their Google profile all the time, there is an option to “Remember this computer for 30 days”. This means that Google will not require two-factor authentication for a month for that particular computer & browser if the user says so.

But how does Google know that this computer is one to be trusted? This information is stored in a cookie. To safeguard my privacy I always setup my browsers to delete all cookies (and LSOs). But this wipes out the Google cookie that “remembers” my machine as well, which means I am asked again and again for 2-factor authentication. This situation quickly gets annoying. Isn’t it possible to tell my browser (Firefox) to delete all cookies EXCEPT the necessary Google cookies every time it exits?

Luckily it is. You need the following settings in Firefox:

  • Accept cookies from sites
  • Keep until: I close Firefox
  • Exceptions…: – “Allow”

This is what your Firefox Preferences window should look like on Ubuntu Linux:

…and the exception window that does the trick – this is how the critical cookies from will NOT be deleted. Instead they will be preserved across browser sessions and you will not have to do two-step verification every time you login to Gmail with computers you trust:

For Windows users, the same options work just fine – here is what the options window need to look like on Windows 7:

…and the exception rule:

Try it. Shut down Firefox, start it up again and have a look in the stored cookies from the main settings panel under Privacy -> Show Cookies. There should only be cookies from “” and perhaps from your browser’s homepage there – nothing else.

You now have

  • Better security of your Google account due to 2-step verification
  • Better usability because you don’t need to perform 2-step verification all the time on your trusted computers
  • Decent privacy & lack of tracking because Firefox deletes almost all cookies every time it exits.

This is the tip of the iceberg (think malware, LSOs, unique browser fingerprints etc), but hey, it’s better than nothing.

* Unfortunately it doesn’t really help when the attacker is the government. As Wikileaks and Privacy International have pointed out with the “Spy Files” project, when it comes to government surveillance Gmail users are screwed.

The financial services industry view on cybercrime

I recently attended Jim Oakes’ “Cybercrime, Global Underground Economy Developments and Challenges” talk. All the hype about his 30-year service for the police, anti-fraud teams, financial services organisations yada yada made me very sceptical to begin with, but the session turned into a quite useful overview of the (depressingly many) ways you can be ripped off by criminals while doing business with/through your bank.

I let this draft lie for a few months now, as I wasn’t sure how to digest the hordes of information in Jim’s presentation into a more friendly, easily digestable message. Shall we just say it’s pretty bad out there?

Practical advice:

  • DO NOT use the same password for different websites. Use something like Oplop to generate passwords and a password manager to store them.
  • DO NOT do eBanking from your smartphone just yet. I have some reservations about the iPhone, but Android phones can certainly currently not be trusted.
  • If you need to do eBanking using a computer (laptop, desktop etc) then start the computer with a bootable CD or USB disk and then do your eBanking. Unless you are personally targeted by law enforcement or criminals, this should give you a computer you can trust. Don’t take my word for it – take Krebs‘ word for it. Computer security is in *such* a sad state.

The myth of the pimples-ridden malware author

Overheard in an Internet Cafe recently:

(guy storms in and purposefully walks towards the counter)

Distressed guy: “Hi, I have a virus on this USB stick and I can´t use it, can you clean it for me?”

Internet Cafe attendant: “…”

Distressed guy: “Look, I didn´t do anything funny, just because some little c*** has nothing better to do but write a virus I can´t access my files now!”

I take issue with this statement. It regurgitates the popular misconception that malware (also known as a virus, a worm, a trojan) is software written by someone who hates mankind. It is their effort to take blind revenge on the world, to mindlessly harm everyone for no real reason other than malice.

Er… no.

Malware takes effort to create. This means skill, patience, equipment and time. All this means money.

Slightly paraphrasing Mikko Hypponen, most malware is created for three reasons:

  1. Money via criminal activities. See Peter Gutmann’s figures in his “The Commercial Malware Industry” from years ago to glimpse at just how much money is involved in this global underground market.
  2. Idealism – which creates the composite term “hacktivism”. Groups like Anonymous fall in this category.
  3. Control – this is state-level information warfare waged either against other nation-states or against the state’s citizens.

Some years ago, malware might have been an annoying prank of kids who had a gripe against the world.

This is no longer the case. Things are far more serious now.