Fort Meade, Maryland (CNN) Summer's high school friends think she's monitoring their phones and listening in on their conversations. They speculate about the "wild things" she does at work and jokingly accuse her of being a spy.

"They like to have fun with it," Summer says. But her friends might be forgiven because when the 18-year-old wasn't in class at her Maryland high school this past school year, she was at her job in the sprawling National Security Agency complex at Fort Meade in Maryland.

There, she works "somewhat in cyber," she responds cryptically when asked what someone in their teens would be asked to do for the NSA, which leads the American intelligence community's electronic signals intelligence gathering and code-breaking efforts.

Equally cagey on that front are Brianna and Simon, two other high school seniors who interned at the NSA, who said over the past year they worked in language translation and cyber, respectively. Their last names are being withheld for security reasons.

The trio -- who are all 18 and just graduated from high schools in Maryland - are among the more than 150 high schoolers in a work study program at the agency which gives them access and exposure to some of the country's most sensitive information and secret efforts. For that they need TS/SCI, more commonly known as Top Secret security clearance, as high as clearances go. No small feat to get ( just ask Jared Kushner ) and a weighty responsibility for anyone, let alone teenagers from a generation that shares everything.

"Before that you don't really understand and then when you get it you realize how much you have access to," Summer says.

'A feeling of responsibility'

"It can be scary," she adds, "because you know what's out there."

Balancing school and work was easy for Simon, who as a senior had enough credits to only need to take two morning classes, then he headed to work in the afternoon. He calls getting top secret clearance a "golden key" that opens up all sorts of doors in the future.

"There's definitely a feeling of responsibility that comes with it," says Simon. "I think it's really cool that they're trusting these young high schoolers with this and so many people are able to get a jump start on future careers with this. I think it's a great opportunity."

Recruiters at the NSA (and other intelligence agencies, like the CIA, have similar programs) know that when it comes to hiring smart, driven, STEM (Science, Technology, Engineering and Math)-minded young people, they are competing with the flashiness and deep pockets of Silicon Valley. So, they aim young and try to dazzle the teens with the work, rather than the paycheck.

"Once they're here they get that sense of purpose from what they're doing every day and they see that they can do things here that they can't do anywhere else," says Courtney, an NSA recruiter. (Her last name is also being withheld for security reasons.)

"We want to get them in and get them hooked early to the mission so they can have a long career here. There's more emphasis now on student programs than I think there's ever been to try to get them when they're young. Get them hooked young," Courtney says.

Silicon Valley 'would be cool' but government work more fulfilling?

Responsibility is one of the keys to getting them hooked. For Summer, that meant joining a team rolling out a new product and giving seasoned officials access to test it (as with everything related to the actual work, details were few and vague).

The money in Silicon Valley "would be cool," she said. "But one of my life goals is to have a job that is kind of fulfilling and I already feel that here."

"I know that I went in and I did something and I helped people ... And having that as one of my goals since I was 12-13, I'm pretty happy," Summer says.

The NSA uses the web, social media and job fairs to recruit students. They didn't go to Brianna's high school, instead, her father suggested she check out intelligencecareers.gov where she started an application process that "was long, with lots of different forms and lots of information."

"The majority of the students we're looking to hire to get them in the door young are in STEM-focused programs..." Courtney said. Interviewers are looking for "lots of experience, certain projects, robotics types clubs."

The profile of the students the NSA is looking for is constantly evolving, she adds, "depending on what the world's demanding, what the country's demanding as far as defending (itself)."

Now, Brianna is part of a program that will see her back at Fort Meade every summer during college, pays her a year-round salary and guarantees her a full-time job at the NSA when she has graduated.

"It was kind of crazy at first, when you walk in, these people are trusting you so much," she says. Now the exciting part is "knowing that I'm helping people and helping keeping people safe, keeping their information safe and doing something that's really necessary."

Not a typical summer job

Restaurants, retail and doctors' offices are where the teens' friends found their jobs, they say, making it impossible to swap work stories, if they even tell friends what they do at all. Brianna doesn't because she's afraid of it getting around, while Simon says his friends don't give him too hard a time.

"I feel a little left out when they get to share their customer service stories," Simon says. "They know that I do government work and are respectful of what I can and can't say."

"They kinda think that's really cool," he says. "They're like, 'Aw, man, really?'"

Even parents are left out, which was hard at first for Summer, whose parents pushed her to join the work study program after seeing the opportunities it gave their older daughter who was also an NSA intern.

"You'd come home and want to tell them I'm doing this, I'm doing this," Summer said. "But then after a while you just kind of get used to it."

High school students graduate, go off to college, travel and get new ideas in their heads. Which is another reason why making the experience as exciting as possible to younger recruits is so vital. Identifying the right hires isn't the challenge, NSA officials say, it's retaining them.

"We try to look further into the future and give them a good experience now so maybe when they're done their college career they'll come back later," Courtney says. "Once they're here they get that sense of purpose from what they're doing every day. And they see that they can do things here that they can't do anywhere else."

Summer, Brianna and Simone are all now college-bound. They don't know exactly what they want to do down the line but all want to stay with the Agency in some capacity in the coming years.

"Catching the bad guys," Summer says, "I look forward to that."