'It is not about if you will be penetrated, but when,' warns NSA chief

Admiral Mike Rogers, director of the National Security Agency, warns that the OPM hack isn't going to be a one-off

Organisations must assume their networks will be breached by cyber criminals and hackers, the head of the National Security Agency (NSA) has warned.

Admiral Mike Rogers, director of the National Security Agency and head of United States Cyber Command, issued the warning while speaking at a cyber security event at the London Stock Exchange.

The warning comes shortly after similar comments by chief information security officer (CISO) for the Met Office Jonathan Kidd. An organisation must assume that its cyber security has already been compromised and develop its strategy from there, he told Computing.

Rogers warned that the US should brace itself more attacks like the one on the U.S. Office of Personnel Management (OPM), which saw the theft of personal details belonging to over 22 million US citizens.

The OPM data breach has exposed details including sensitive information about 19.7 million current, former and prospective federal government employees who applied for clearances, along with 1.8 million non-applications including partners and flatmates. Rogers suggested that the OPM hack isn't going to be an isolated incident.

"I don't expect this to be a one-off," he said, according to The Wall Street Journal, before describing one of the key questions in the fight against cyber crime is "what is the right vision for the way forward in how we are going to deal with things like this".

Rogers also warned the London Stock Exchange audience that it's not a case of if their networks will be breached by hackers, but when.

"We are in a world now where, despite your best efforts, you must prepare and assume that you will be penetrated," he said. "It is not about if you will be penetrated, but when."

One way to combat the threat, Rogers argued, is for greater collaboration between government and businesses when it comes to protecting against cyber threats.

"Cyber to me is the ultimate partnership. There is no single entity out there that is going to say: 'don't worry, I've got this," he said.

While the perpetrator of the OPM hack isn't currently known, director of national intelligence James Clapper has suggested that China is the "leading suspect".