Canada's foreign signals intelligence agency says it's struggling to find Canadians to fill vacancies as it grows its presence online.

The Communications Security Establishment (CSE) grew another head last year when it launched the Canadian Centre for Cyber Security.

The centre leads the government's response to cyber security events, defends Ottawa's cyber assets and provides advice to Canadian industries, businesses and citizens on how to protect themselves online. An average day can see the hub's team block more than 100 million malicious infiltration attempts.

Those responsibilities ramp up the pressure on CSE to hire the best hackers and codebreakers Canada's universities can supply. A number of internal CSE employees also shuffled over to the centre to get it up and running, creating vacant positions.

"We don't necessarily know all our needs right now. We have a lot of vacancies because we're growing massively," said Bruno Gervais, supervisor of the Communications Security Establishment's recruitment team. He made a presentation at a career fair in Ottawa Friday aimed at recruiting people in the intelligence and security fields.

"We don't have enough technical candidates for a number of positions we have. This is a bigger challenge."

Gervais said CSE needs to hire about 150 full-time employees next year and roughly 300 students to fill those gaps.

The secretive Communications Security Establishment (CSE) is headquartered at a complex in Ottawa. (Sean Kilpatrick/Canadian Press)

To work for the CSE, an applicant has to be a Canadian citizen and pass a top secret clearance process, and cannot have a criminal record. The stringent background check alone can take more than a year to complete.

The CSE's first pitch session Friday morning was packed, with roughly 150 people jammed into limited seating and dozens of others standing in the back to hear the recruiters' pitches.

The audience was split between students and grey-haired veterans. Some wore suits. Others sported hoodies and bedhead.

Low hiring ratio

Gervais said that for every 100 applications he gets, only one will make it through the process — two if he's lucky.

The CSE isn't alone in its struggle to hire new recruits.

Canada's spy agency, the Canadian Security Intelligence Service (CSIS), has flagged issues with recruitment and retention, while the Royal Canadian Mounted Police has also cited its need to hire more cyber experts.

Both agencies also had booths at this year's career fair, along with the Financial Transactions and Reports Analysis Centre of Canada (FINTRAC, which deals with financial intelligence) and Public Safety Canada.

"There's a lot of competition. All the Googles, Facebooks, Amazons and all these startups. The demands are really high. The universities are kind of adjusting right now," said Gervais.

"Most of the companies have the same problem right now, not just in the government. The fact that we're looking for Canadian citizens doesn't help because there's a lot of non-Canadians in all these programs in universities."

The CSE has tried to get creative with its recruitment strategies. In the fall it partnered with an Ottawa-based company that runs recreational "escape rooms"; those who escaped the demo room on time and cracked a bonus puzzle got a chance to meet with a CSE recruiter.

"We still have a problem letting people know who we are," said Gervais. "The biggest barrier for us is people don't know who we are."