New and surprising password guidelines released by NIST

21. December 2017

The National Institute of Standards and Technology (NIST), a non-regulatory federal agency within the U.S. Department of Commerce that promotes innovation and industrial competitiveness often by recommending best practices in matters of security, has released its Digital Identity Guidelines uttering advice for user password management.

Considering that Bill Burr, the pioneer of password management, has admitted regretting his recommendations in a publication back in 2003, the NIST is taking appropriate action by revising wide-spread practices.

For over a decade, people were encouraged to create complex passwords with capital letters, numbers and „obscure“ characters – along with frequent changes.

Research has now shown that these requirements don’t necessarily improve the level of security, but instead might even make it easier for hackers to crack the code as people tend to make minor changes when they have to change their already complex password – usually pressed for time.

This is why the NIST is now recommending to let go of periodic password change requirements alongside of algorithmic complexity.

Rather than holding on to these practices, the experts emphasize the importance of password length. The NIST states, that „password length has been found to be a primary factor in characterizing password strength. Passwords that are too short yield to brute force attacks as well as to dictionary attacks using words and commonly chosen passwords.“

It takes years for computers to figure out passwords with 20 or more characters as long as the password is not commonly used.

The NIST advises to screen new passwords against specific lists: „For example, the list may include, but is not limited to passwords obtained from previous breach corpuses, dictionary words, repetitive or sequential characters (e.g. ‘aaaaaa’, ‚1234abcd’), context-specific words, such as the name of the service, the username, and derivatives thereof.“

Subsequently, the NIST completely abandons its own suggestions and causes great relief for industries all over:

„Length and complexity requirements beyond those recommended here significantly increase the difficulty of memorized secrets and increase user frustration. As a result, users often work around these restrictions in a way that is counterproductive. Furthermore, other mitigations such as blacklists, secure hashed storage, and rate limiting are more effective at preventing modern brute-force attacks. Therefore, no additional complexity requirements are imposed.“