The National Institute of Standards and Technology (NIST) has updated its guidance on strengthening passwords, suggesting the standard of using a combination of capital letters, lower case letters, numbers and special characters may not be effective at improving password strength. The problem is not with this method of strengthening passwords, but with end users.
Hackers and other cybercriminals attempt to gain access to accounts by guessing passwords. They try many different passwords until the correct one is guessed. This process is often automated, with many thousands of guesses made using lists of commonly used passwords, dictionary words and passwords discovered from past data breaches.
By implementing password policies that force end users to use strong passwords, organizations can improve their resilience against these brute force attacks.
By using capital and lower-case letters, there are 52 possible options rather than 26, making the guessing process much more time consuming. Add in 10 numerals and special characters and guessing becomes harder still. There is no doubt that this standard practice for creating strong passwords is effective and makes passwords much less susceptible to brute force attacks.
The problem is that in practice, that may not be the case. Creating these strong passwords – random strings of letters, numbers and symbols – makes passwords difficult to guess but also virtually impossible to remember. When multiple passwords are required, it becomes harder still for end users and they get frustrated and cut corners.
A good example is the word ‘password’, which is still – alarmingly – used to secure many accounts, according to SplashData’s list of the worst passwords of the year. Each year, ‘password’ makes it onto the list, even though it is likely to be the first word attempted in any brute force attack.
When companies update their password polices forcing users to use at least one capital letter and number in a password, many end users choose Password1, or Passw0rd or P455w0rd. All would be high up on a password list used in a brute force attack.
Attempts such as these to meet company password requirements mean security is not actually improved by password policies. If this is going to happen, it would make more sense – from a security perspective – to allow employees to make passwords easier to remember in a more secure way.
NIST Tweaks its Guidance on Strengthening Passwords
As NIST points out in its guidance on strengthening passwords, “Analyses of breached password databases reveal that the benefit of such rules is not nearly as significant as initially thought.” With current standard password practices, “The impact on usability and memorability is severe.” That results in end users creating weak passwords that meet company password policies.
Rather than force end users to use special characters and end up with ‘Password!’, a better way would be to increase the length of passwords and allow the use of spaces. End users should be encouraged to choose easy to remember phrases.
The use of a space does not make a password any more secure, although increasing a password from 8 characters to say, 15 or 20 characters, certainly does. It also makes passwords much easier to remember. NIST suggests passwords must have a minimum of 8 characters, and that “Users should be encouraged to make their passwords as lengthy as they want, within reason.”
NIST also explains in its guidance on strengthening passwords that certain types of common cyberattacks involving passwords are unaffected by password strength. Take phishing for instance. It doesn’t matter whether a password is ‘12345678’ or ‘H19g46”&”^’ to a phisher. Provided the phishing email is well crafted, the password will still be disclosed. The same applies to keyloggers. A keylogger logs keystrokes and the strength of the password is irrelevant.
NIST’s guidance on strengthening passwords also suggests that rather than strengthening passwords further, there are far more effective ways of making brute force attacks much harder without frustrating end users. Limiting the number of failed login attempts before a user is blocked is one such option. Organizations should also combine this with blacklists of unacceptable passwords that should include dictionary words, other weak passwords and those revealed from past data breaches. NIST also recommends secured hashed storage of passwords
The NIST guidance on strengthening passwords can be found in – NIST Special Publication 800-63B – Appendix A – Strength of Memorized Secrets