Smartphone users shouldn't be too concerned about the FBI's successful hack of an iPhone, as one digital security expert says the security breach is extremely difficult to replicate.

Digital forensics expert Ryan Duquette says the FBI used special tools and the help of an outside company to hack into a mass shooter's iPhone, after Apple refused to help with the process.

"The methods and the company that was being used to do this are very specialized. Not everybody has these tools and the methods to do this," Duquette told CTV's Canada AM on Wednesday.

That means most hackers won't be able to repeat the process with a simple how-to tutorial from YouTube, he said. However, "criminals are obviously watching very, very closely," he said.

The FBI had argued in U.S. court that Apple should be forced to help it unlock the iPhone of Syed Farook, who was shot dead by police after he and his wife gunned down 14 people in San Bernardino in December.

Apple had steadfastly refused to help breach its own security, so the FBI enlisted a private company to get the job done.

Duquette said the company found a way around Apple's password security feature, which usually shuts down the phone after 10 incorrect passwords are entered. The hack allowed the FBI to try a multitude of possible passwords to unlock the phone.

"If this was a vulnerability in Apple's code that this company was able to get past, Apple will close that hole," Duquette said. That means the company will likely release a software update to prevent the hack from working again, once it identifies how it was done.

Duquette said iPhone users shouldn't worry about someone using the FBI's method to crack their phones. Users are more likely to be hacked through an unsafe website or app, he said.