According to a new study, hackers can crack short and simple passwords in a matter of seconds, while long and complicated passwords can take trillions of years. Researchers in Virginia suggest that even an eight-character password -- with a bunch of numbers, uppercase letters, lowercase letters and symbols -- can be cracked within eight hours by the average hacker. Anything shorter or less complex could be cracked instantly by any hacker who knows what they're doing. But passwords that are 18 characters in length could take up to 438 trillion years for the average hacker to crack.
Source: NBC Washington