On Thursday, at the Collision Conference in New Orleans, Nico Sell took the stage wearing thick, dark, shades -- a measure, she says, for reducing her digital footprint and keeping her family safe.

Sell is the co-founder of Wickr, a company she boasts as the only encrypted messaging service that has yet to be publicly hacked. An advocate for cyber-security, Sell has worked with U.S. spies and with General Keith Alexander, the former Director of the National Security Agency (NSA), on matters of global security.

She's also supportive of large-scale technology companies, including Apple, refusing to hand over encryption keys to the FBI. Shortly after mass shootings took place in San Bernardino, California last year, the bureau had requested the software company's help in breaking into the iPhone of a gunman. The company refused to do so, on the grounds that bypassing security features on the device could threaten security for all Apple users. Ultimately, just one day before Apple was expected to face off with the FBI in court, the bureau announced that it had acquired third-party hacking software for a massive sum, and was able to break into the device on its own.

"It's the job of the FBI, and others, to find ways to break in, but it's not the technology vendor's job to break into their system," Sell insisted, speaking in conversation with Steven Levy, a journalist and founder of Backchannel.com, in New Orleans on Thursday afternoon.

Personal privacy, argues Sell, is a matter of international security, which is why her San Francisco-based company has more of these features in place than most apps do. Although competing messengers such as Viber and WhatsApp do encrypt user data, Wickr goes so far as to operate without any visible infrastructure.

"The big reason why spies and activists use us is that Wickr doesn't have activity logs," she explained. "We don't see who is talking to who, when, and how often, which is just as important as the content of the message."

Among spies and international activists, users of Wickr include, of course, security-minded teenagers. To date, the company has raised nearly $40 million in venture capital funding, from investors including Breyer Capital and Juniper Networks.

Sell may empathize with Apple CEO Tim Cook when it comes to bartering with the U.S. government. She admits that "pre-Snowden," meaning prior to when former government worker Edward Snowden leaked classified NSA security documents showing global surveillance programs were being conducted by the NSA, as well as by major telecom companies, she, too, was approached by an FBI agent to provide a "back door," so to speak, for her messaging service.

"I told the FBI that, look, you and I are on the same side here, but I'm not going to put a back door in our system, because it's not good for you, and it's not good for me," Sell said.

Of course, the matter is a contentious one. Many argue that companies such as Apple, or Wickr, have a responsibility to hand over access to data when it could help fight terrorism, or another national security threat. Sell, for her part, says she is fulfilling those responsibilities -- just not in the ways that the public might expect her to.

"Apple helps the government all the time. We help the government all the time," she continued, referring to the use of her technology by U.S. spies. "What they asked Apple to do in this [the FBI] case was compel them to write code, new code to change their system. And code that they considered dangerous."

She sees this as dangerous on a number of fronts: "If the government can come to us and tell us to rebuild our system so that they can have lawful intercept, that should scare everyone in this room. Because no technology company is going to survive in the United States under that environment."

When pressed by Levy, Sell admits that adversaries, including ISIS, are likely using Wickr.