Do we really need strong passwords? | Naked Security
They also set out to determine just how strong a password used on a website needs to be to withstand a real-world attack.
Their conclusion is that creating strong passwords is wasted effort a lot of the time.
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The conclusion of the report is that there are effectively two kinds of passwords: those that can withstand one million guesses, and those that can withstand one hundred trillion guesses.
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Systems administrators, they say, should stop worrying about getting users to create strong passwords and should focus instead on properly securing password databases and detecting leaks when they happen.