How many guesses per second

An attacker must input the username and password exactly, as changing the hash even just a tiny bit as seen above will result in a completely different hash. Assuming a password only consists of lowercase letters, for each character there are 26 possibilities. Therefore, you would expect to be able to guess a one-character password within 13 attempts.

Adding an extra character to a four-character password, using only lowercase characters, makes it 26 times more difficult to crack, whereas doubling the possible characters to 52 i. A regular computer would likely make about , guesses per second. If we assume the attacker has a regular computer, capable of , guesses per second, any lowercase password with less than six characters will take less than one minute to crack. But the solve-time increases exponentially, and an eight-character password would take 12 days to crack.

A character password would take over 12, years. Whether a character password is enough depends on the value of what it protects and the scale of the attack. If attackers are only after a single target, a character password might be within their reach.

When encrypting your Bitcoin wallet, for example, a key of over 32 characters might be a good idea. The above calculations assume that the attacker does not know anything about the password, other than whether it includes uppercase or lowercase characters. In reality, the attacker might have some guesses. From previous decrypted password lists we know what the most common passwords are.

If there is no specific target, an attacker could check common passwords with an email list relatively quickly. People also tend to choose passwords that only have numbers at the end such as hello , and include the name of the service or URL somewhere. A recent survey suggests there are, on average, passwords per person.

The good news is there are tools to address these issues. Most computers now support password storage in either the operating system or the web browser, usually with the option to share stored information across multiple devices. Read more: Facebook hack reveals the perils of using a single account to log in to other services. Festival of Social Science — Aberdeen, Aberdeenshire. Edition: Available editions United Kingdom. Become an author Sign up as a reader Sign in.

Paul Haskell-Dowland , Author provided. Online security Cybercrime Passwords Online safety password managers password protection password security.

In fact, since it is one character longer and contains uppercase, lowercase, a number and special characters, that first password would take an attacker approximately 95 times longer to find by searching than the second impossible-to-remember-or-type password! Sure, it might be. But that doesn't matter, because the attacker is totally blind to the way your passwords look. The only thing an attacker can know is whether a password guess was an exact match.

The attacker doesn't know how long the password is, nor anything about what it might look like. So after exhausting all of the standard password cracking lists, databases and dictionaries, the attacker has no option other than to either give up and move on to someone else, or start guessing every possible password.

Once an exhaustive password search begins, the most important factor is password length! If every possible password is tried, sooner or later yours will be found. We Have a Problem!! What happens here, stays here. Enter and edit your test passwords in the field above while viewing the analysis below.

Note that typical attacks will be online password guessing limited to, at most, a few hundred guesses per second. If so, you'll have noticed that the first, stronger password has much less entropy than the second weaker password. For example, a password that would take over three years to crack in takes just over a year to crack by Five years later, in , the cracking time drops to four months. By , the same password could be decoded in just over two months.

This demonstrates the importance of changing passwords frequently. Your login history looks odd. You have a pile of bounce-back messages in your inbox and a bunch of strange messages in your sent box. First, recover your email account, and change your password use our guidelines to formulate a strong one. Complete all the steps, such as changing security questions and setting up phone notifications.

Because email is filled with personal information, you should also notify your bank, PayPal, online stores, and any other accounts to discern whether a breach has occurred.

Be sure to change other passwords as well. Finally, notify your contacts in case emails sent from your account have compromised their information too. While not getting hacked at all is the best-case scenario, promptly taking these steps can make the best of a bad situation. As time goes on, it only becomes more likely that your password will be hacked — putting your most personal information at risk.