Android screen lock bests FBI


22 Responses to “Android screen lock bests FBI”

  1. haineux says:

    Even if they are, technically, “Security by obscurity,” sufficiently difficult computer security schemes rapidly cause people to switch to another attack mode, in this case, judicial.

    • Every security system relies on some form of obscurity. Passwords, keys, and patterns are not security by obscurity.

      That said… the real downside to pattern unlock is sometimes you can find out the pattern just by looking at the grease smudges on the phone.

      • digi_owl says:

        reminds me of the old trick about the worn out buttons on a keypad. Sure, your missing the sequence. But you have strongly reduced the number of combinations.

    • Shashwath T.R. says:

      No, that’s not security by obscurity – a password is a secret, but the method by which it works is not obscure by any means.

      Using (say) RSA keys is not security by obscurity, but using your own made up cryptographic system would be…

  2. Douglas Gardner says:

    Couldn’t they just look at the grease smears invariably left on the phone?

  3. elix says:

    I guess they haven’t heard of the crescent wrench cipher

  4. Steve Mayne says:

    Not to mention that modern Android phones have the option to encrypt their entire storage – so dismantling the phone wouldn’t get them any closer to their goal.  

    • phisrow says:

      The key to the encrypted blob is still on the phone somewhere(the swipe-unlock doesn’t provide enough entropy for a crypto key, so most or all of the key has to be stored somewhere).
      Now, depending on implementation, the stored key might be in tamper resistant memory of some kind, and liable to nuke itself if you start poking around where you don’t belong…

  5. I don’t understand how exactly did they manage not to open it, am I missing something?…
    Encrypted storage or not, all Android phones can boot into recovery mode. While in recovery mode, a custom recovery image, usually used when rooting and customizing, can be installed. That custom recovery image allows one to back up the entire internal memory onto the SD card, and it also allows you to mount the SD card and get that backup off it without ever booting far enough to get the pattern lock. And you usually can just remove the SD card and read it separately.Even without replacing the recovery image, with most models you should be able to backup all the data with ADB once you boot into recovery mode and unlock debug functions with the ADK, why couldn’t they do that?

    • failquail says:

      I was about to post something similar myself.

      It’s quite easy to dump image files of the internal storage to sdcard.
      Of course then it’s a bit more involved getting the data you want from that, but certainly not impossible.

      • From the digital forensics POV this should be the preferred method in the first place, since software can’t decide the phone is compromised and wipe everything if you imaged the whole thing.

  6. jackie31337 says:

    Really, FBI? My daughter was able to defeat the screen lock on my husband’s tablet when she was 7. She just watched him unlock it and copied the pattern. His finger grease on the screen probably helped, too.

    • SamSam says:

      Yeah… that’s totally like that movie, where the FBI didn’t know the guy’s password and I was like “Really FBI? I saw the guy type “swordfish” in the first five minutes of the movie!!! Weren’t you guys paying attention?”

  7. lyd says:

    The lockout after 5 attempts prompts you to reset the lock by entering your google account creds.  Why wouldn’t the FBI just subpoena google to surrender the account info?

    • wysinwyg says:


      Entering repeated incorrect patterns will cause a lock-out, requiring a Google e-mail login and password to override. Without the Google e-mail login and password, the cellular telephone’s memory can not be accessed. Obtaining this information from Google, per the issuance of this search warrant, will allow law enforcement to gain access to the contents of the memory of the cellular telephone in question.

  8. Mattias Björkas says:

    I have always wondered why the Android phone lock is designed the way it is. Even if you catch an unintentional glimpse of the screen when it’s being unlocked by someone, the colourful, graphichal representation of the swipe pattern simply becomes etched into your retina, after which you can easily replicate the swipe. This is a fun feature if the person unlocking is a friend, but if not, I only feel uncomfortably tempted to move into the world crime.

  9. liveTexas says:

    Why is everyone pointing out Their “unlocking strategy”?
    Write an App & use AdWords or something !

  10. Hey, we found a simple way to gain unlimited attempts at gesture unlocking an Android phone and shot a video walk-though. If the FBI had done this, they would not have to have subpoenaed Google for the phone owner’s credentials. Here’s our write-up:

  11. OoerictoO says:

    or they could have just compelled the user to reveal their password/pattern.  recent precedents show this does not fall under 5th amendment protection.  which is a farce, IMO.  and yeah, what others said about recovery mode backup…

    didn’t we have this conversation last week?

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