Pasting of passwords improves security, says National Cyber Security Centre

Email security - Image credit: Daniel Reinhardt/DPA/Press Association Images

Organisations should stop preventing people from pasting passwords, because the pros far outweigh the cons, the National Cyber Security Centre has said.

According to the centre, allowing users to paste their passwords into forms improves security, while efforts to stop it actually reduces security.

“We believe [stopping password pasting] is one of those 'best practice' ideas that has a common sense instant appeal that may have made sense once.

“Considering the bigger picture today, it really doesn't make sense,” the centre said in a blog post.

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It argued that the main benefit to allowing password pasting is that it allows people to use a password manager – software that chooses, stores and enters passwords automatically into online forms.

This means users can have a number of different, more complex passwords for the sites they use without having to remember them.

However, if users can’t use a password manager they are more likely to fall back on other bad habits to make sure they can log into a range of websites, such as re-using the same password, choosing simple, easy to guess passwords, or writing them down somewhere that is easy to find.

The centre said that a number of the reasons used to justify stopping password pasting may be persuasive but are “misleading”.

For instance, it said, the idea that password pasting makes the password easier to forget is true in principle, but in practice people have to set up so many passwords they rarely get chance to practise each one anyway.

Meanwhile, the post said that the idea password pasting allows brute force attacks – where malicious software repeatedly guesses until it breaks the password – is true to some extent, but added that there were other ways to make guesses that are “just as easy for attackers to set up and are much faster at guessing”.

Addressing a third concern that password pasting leaves a copy of the password on the computer’s clipboard that could be stolen by malware, the centre advised that – rather than stopping password pasting – teams should “inoculate” their computers so they don’t get the malware in the first place.

The centre’s statement follows one published at the end of 2016 that challenged the received wisdom of having automatic password expiry, saying that it was a “blunt instrument” that actually made accounts more vulnerable.

“Password expiry might initially look like a quick and easy way of helping to manage the risks.

“However, it rarely delivers the headline benefits it promises, and mostly just creates fresh vulnerabilities instead,” the centre said at the time.