A.P. Lawrence

Change your password four times a minute!

A Swiss researcher has developed a way to crack Windows passwords in an average of 13.6 seconds according to this: http://news.com.com/2100-1009_3-5053063.html?tag=fd_top

A quote from the article:

The result: The same password encoded on two Windows machines will always be the same. That means that a password cracker can create a large lookup table and break passwords on any Windows computer. Unix, Linux and the Mac OS X, however, add a 12-bit salt to the calculation, making any brute force attempt to break the encryption take 4,096 times longer or require 4,096 times more memory.

Well, that is 15 hours, which is a bit long, but keep in mind that the very first thing someone needs is your encrypted passwords. Although this article doesn't point this out, on Unix and modern versions of Windows, you can't get those without root or administrative access. It is unfortunately true that Windows has suffered from a lot of security flaws that can be used to gain such access fairly easily, but Unix hasn't been immune to that either.

I offer a simple solution for this. Unix users need to change their passwords twice a day, and their Windows brethren should do so four times each minute.

Seriously, my experience it that people don't understand the need for strong passwords nor what a good password is. Just the other day I set up a user for ssh access to the corporate system and, after explaining that we couldn't use the "same as your login " scheme that was used inside the building, asked her for a password. With a conspiratorial flair, she turned away and wrote something on a small piece of paper, which she then carefully cupped in her hand to show to me. It said: ALPHA

That's not a good password. It's not even close. A good password needs mixed upper and lower case, numbers, and punctuation. Passwords like "ALPHA" don't need root or administrative access: they can be guessed with simple dictionary attacks.

One way to make up passwords that are both good but easy to remember is to use a phrase you can remember (perhaps from a song or a poem) and get creative with it. For example, "There must be 50 ways to save money!" becomes "Tmb50!w27m" ("seven" for "save" and moving the exclamation after 50), and "I just hate to forget MY password!" is "Ijh824gM!p".

Finally, although it is very tempting to use the same password everywhere, don't. A trick I use is to have a very long, phrase generated password. The phrase I use falls very naturally into two parts, which gives me quite a few easy to remember passwords:

• The first part
• The second
• First followed by second
• Second followed by first
• First backwards
• Second backwards
• First followed by second backwards
• Second followed by first backwards
• First and second, all backwards
• Second and first, all backwards.
• All of the above with 2-3 leading or trailing extra punctuation characters.

While I may not instantly remember which I used at a given place, I can usually get it within a few tries. But if someone should get hold of one of my passwords, they aren't going to have instant or easy access to everywhere else.

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