LinkedIn has introduced improved security, designed to avoid past breaches of user content.

Unveiling a new two-factor authentication process, the professional social networking site says the move "adds another layer of security to your LinkedIn sign-in."

"At LinkedIn, we are constantly looking for ways to improve the security of our members' accounts," wrote Vicente Silveira on the company's official blog post.

"All LinkedIn accounts are already protected by a series of automatic checks that are designed to thwart unauthorised sign-in attempts.

"Now, we are introducing a new optional feature that adds another layer of security to your LinkedIn sign-in: two-step verification."

Providing instructions to its 225 million users, LinkedIn hopes the move will prevent a repeat of major breach this time last year, when hackers revealed millions of user passwords.

"Most internet accounts that become compromised are illegitimately accessed from a new or unknown computer (or device)," Silveira wrote.

"Two-step verification helps address this problem by requiring you to type a numeric code when logging in from an unrecognised device for the first time.

"This code will be sent to your phone via SMS.

"When enabled, two-step verification makes it more difficult for unauthorised users to access your account, requiring them to have both your password and access to your mobile phone.

Users can turn on two-step verification by going to Settings, selecting the Account tab and clicking Manage security settings option.