Tag Archives: xkcd

Perpetuating Password Myths

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Brute force cracking

Brute force cracking

Today at work I got an e-mail from the IT department saying everyone needs to set new, stronger, passwords.1 They suggested several things, like:

  • “tomandjerry” is not as strong a password as “$H2mlf”
  • “Fishing123” is not as strong as “Fish123ing”

Assuming a black hat hacker is really determined to crack your password, they’re probably going to attack it like they mean it.  Let’s assume there’s no defect in your system that allows a cracker to get in without actually entering the correct password.  They might try a dictionary attack first, followed by a database of common passwords, but after that they’re left with brute force.

Here’s the most amusing part.  Assuming none of the four “passwords” above are in any dictionary or a database of common passwords.  Let’s rank the passwords, 1 being the strongest and 4 being the weakest.

  1. “tomandjerry” is strongest, with 11 characters
  2. Fishing123″ is tied exactly with “Fish123ing”, with 10 characters each
  3. “$H2mlf” is weakest, with only 6 characters

The only things that really matter in passwords are that you’re not using (a) a dictionary word or a common password and (b) the length of  your password.2

In any case, it’s concerning when information technology professionals don’t understand fundamentals of password security or how a malicious attacker would attempt to compromise a system.

  1. Photo courtesy of akashgoyal [↩]
  2. If you’re using a multi-word password, it is possible an attacker knowing this could use a system that combines words – but this doesn’t really save them a lot of time – we’re talking about numbers with 20-30 zeros in them [↩]

DrawBot – Onwards and Upwards!

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A few thoughts about operating a DrawBot, in semi-organized fashion:

  • Vertical Surface Drawing.  There is an interesting tension in the design of a vertical line-driven drawing robot.  As the drawing surface orientation approaches horizontal, the easier time the robot will have using a standard pen to draw, the more difficult it will be to control the drawing component via a line system, the  greater the weight that would be required,1 a greater weight puts a greater stress on the line and the motor and has some effect on the responsiveness of the drawing component, and the more the weights on the drawing component would be in contact with the drawing surface – possibly causing smudges.  The closer the surface is to vertical, the easier it will be to actually operate as a line-driven robot, the less weight required,2 but the more difficult it would be to have a pressure from the drawing component on the drawing surface.
  • Robot Portability.  Right now my robot is quite portable – and, of course, there are costs and benefits associated with this.  Right now I’m limited to the “size” of my robot at 2’x4′ since that’s the size of the piece of plywood I bought and on which the motors are mounted.  However, it is very easy to just move the robot by putting the plywood in a different location in the house.
  • Robot Location.  This is, in some senses, the flip side to robot portability.  I’d love to put the ‘bot up on the wall and draw something really really huge.  I don’t see that happening until I’m more comfortable running the robot, have found a better pen/paper combination, and – perhaps most importantly – figured out how to run the robot wirelessly or off an SD card.
  • Drawing To-Do’s:  Ideally, I’d like to put the robot to work drawing something on an epic scale.  A high resolution photograph of earth, moon, or pretty much anything from NASA.  Perhaps a map of middle earth, the 100 acre woods, or the Princess Bride story?  A photograph of the world at night, with highlights of the world’s electricity consumption.  Or, some of the INSANELY awesome super sweet posters from various XKCD comics.
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  1. This my theory, anyhow.  My reasoning is that as the surface approaches horizontal, the more weight you’d need to pull at the drawing component because more of the force of the weight would be absorbed directly by the drawing surface itself – along with some friction as it passes over the surface as well. [↩]
  2. See reasoning regarding weight above. [↩]

Yes, I will fix your computer

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Tech Support Cheat Sheet

Tech Support Cheat Sheet

I have a rule for all of my friends.  I will fix their computers for free, twice.  :)

It’s a good rule and it has helped my friends and myself on many an occasion.  Contrary to the impressions of those unfamiliar with the inner workings of their own computers, diagnosing and fixing a computer problem is not a matter of innate knowledge.  It’s basically 50% making common sense interpretations of errors and common sense changes to settings and 50% Googling for the answer.

Given fixing computers can be tremendously time consuming, WHY would I spend my free time fixing them for free?  Simple.  My rule is, I’ll fix your computer twice.  First time, you give me your broke down computer and I get the OS working, repair whatever it is, and give it back to you good as new(ish) and if there’s a problem with it again, you give it to me to fix again.  Second time, you give me your broke down computer and I get the OS working, repair whatever it is, and I keep it.

Oh, and if you want to know why you should never help someone with their computer problems unless it is really dire, check out this Dilbert comic.

Dilbert

Dilbert