Long password is safer than a complicated one
In stead of short, complex and not easy to remember password, let's think about using the long one. This involves in combining words to gain a string at least 15 characters" said by a security expert at weekly technology consultation at FBI office. "The longer password is, the harder it can be cracked, also it is easy for you to remember".
For a long decade, there has been controversies about whether a password with as many as characters as possible, even simple characters, is safe as a short one with full of special characters, capitals, lowercases and numerals.
FBI leans toward the first opinion. In the viewpoint of FBI expert, the longer password is, the more time and resources cracking system need to compute. Meanwhile, short password contains characters and numerals that are difficult to remember and can be decoded easily.
An academic research published in arXiv, in 2015 also supported the FBI's argument. The report explains that "the effect of increasing alphabet strings' length leads to increasing complexity of the password"
However, FBI also recommend that it should not be too simple when setting passwords. In stead, they can use the popular approach called XKCD - which implies an entire password included one or several words that don't have phonetics or meaning but they are still easy to remember.
In 2017, the National Institute of Standards and Technology (NIST - an agency of Technology Governance Department of US Commerce Department) also urged web service to support XKCD instead of using other types of password. The guideline of NIST in November also encouraged users to try passphrase rather than single words.