Are password rules just bad magic?
'Eye-of-newt' rules may not help, consultant says
- By Michael Hardy
- May 18, 2010
Readers continue to flood us with suggestions for creating and remembering strong passwords, as our challenge continues. However, at least one reader believes the conventional wisdom on passwords is wrong.
Blogger William Cheswick, in his own report on the password theft that prompted our original article, noted the three commonly accepted rules of a good password:
- It should contain at least eight characters.
- It should contain a mix of four different types of characters (uppercase letters, lowercase letters, numerals and punctuation symbols).
- It should not be a name, a slang word, or any word in the dictionary.
"I call these eye-of-newt password rules, because the recipes are reminiscent of magical potions," Cheswick wrote.
Another common rule – to never write passwords down – seems to be fading, he added. "Previous admonitions against writing down passwords contemplated local attacks – people reading your Post-it notes on your terminal in the office for example," he wrote. "Most attacks come from distant malefactors, and they will never see your terminal. But do beware of leaks to family members, like curious teenagers or a divorcing spouse."
However, Cheswick said, the rules against using words, or requiring mixing of character types, are also a lot less relevant in today's security climate.
"Dictionary attacks are no longer a common threat to most Internet users. Passwords are usually obtained by keyboard sniffing software or phishing Web sites. Under these threat models, all the eye-of-newt rules are what many users suspected: annoying, tedious bureaucratic rules that don't actually help security!" he wrote.
For example, the 32 million passwords that security firm Imperva analyzed (reported in our earlier stories) were stolen, not guessed. "It didn't matter what kind of password the 32 million people chose: the bad guys got all of them, strong and weak, for reasons beyond the users' control," Cheswick said. "It was the site administrators who screwed up."
Cheswick offers two ideas to improve security without using eye-of-newt:
1. One-time passwords: These require tokens – which may be hardware or software – to generate the passwords. However, they're valid for only one log-in, so if someone steals the password, it will be useless. "This has been tried, but it hasn't caught on. It seems to me that it is time to try again," Cheswick said.
2. The "don't be a moron" rule: Create systems that lock an account after a small number of incorrect tries to log in. The users are then responsible to not be morons, Cheswick said. Feel free to use a common word as a password, but not one that's obviously connected to you – no names of pets or spouses, no passwords that match the name of the site they're for, no sequences of numbers.
The combination of putting a little thought into the password and having accounts that will lock after a few wrong guesses allows users to create simple and memorable passwords, while minimizing the risk of unauthorized access.
Meanwhile, your password ideas continued to flow in.
Some readers suggested technological aids, devices that can securely store passwords, to be retrieved when needed.
"A truly strong password is only used on a single system and not reused," wrote one anonymous commenter. "It is impossible to do that consistently across the hundreds of accounts that I personally have. My solution to this is to only have easily memorable passwords for often (daily) used accounts. For all other accounts I use a password generator and storage utility called KeePass. This utility securely generates and stores very complex nonsensical passwords for most of my accounts. When I need it, I open the store with a very secure memorable password and then retrieve the password for use."
Jay Daughtry, from Potomac Falls, Va., said the method that a coach signals the next play to a batter is useful in creating passwords. "The coach could make all kinds of gestures, but until he hit the 'key,' none of it mattered," Daughtry wrote. "The key is the sign that says the next sign is really what is to be done (steal, bunt, etc.). So, how does this relate to the creation of passwords? Start all of your passwords with the same combination of characters and use at least two to three of the requirements (lower case letters, upper case letters, numbers, special signs). What follows this key can be a simple word and/or number that is easy to memorize."
John in San Diego takes a Borscht Belt approach: "I use the initial letters of punchlines to corny old jokes and numbers from one of my 39 'permanent' street addresses. 'That was no lady, that was my wife' becomes Twnltwmw_1725."
Sandy Ingrassia, from Buckley Air Force Base in Colorado, offered a simple algorithm: "My idea is to take a phone number you have memorized (not your own), to include area code. Then you could start with the number, then on the phone pick a letter of the next number and use that as a capital, then go to the keyboard and add a special character for another number and so on. Just make sure that you keep a rhythm (i.e. number, capital, symbol, lower case, repeat) so you remember the order."
Keep your comments coming, and let us know if you agree or disagree with Cheswick's thoughts as well. We'll hold the contest open until May 24, and the submitter of the best password idea – as judged by the Government Computer News editors – wins a T-shirt.