Former U.S. Army intelligence analyst Chelsea Manning says censorship is still "a dominant threat," advocating for a more decentralized internet to help better protect individuals online.

Her comments come amid ongoing tension linked to online safety rules, with some tech executives recently seeking to push back over content moderation concerns.

Speaking to CNBC's Karen Tso at the Web Summit tech conference in Lisbon, Portugal, on Wednesday, Manning said that one way to ensure online privacy could be "decentralized identification," which gives individuals the ability to control their own data.

"Censorship is a dominant threat. I think that it is a question of who's doing the censoring, and what the purpose is — and also censorship in the 21st century is more about whether or not you're boosted through like an algorithm, and how the fine-tuning of that seems to work," Manning said.

"I think that social media and the monopolies of social media have sort of gotten us used to the fact that certain things that drive engagement will be attractive," she added.

"One of the ways that we can sort of countervail that is to go back to the more decentralized and distribute the internet of the early '90s, but make that available to more people."

Asked how tech companies could make money in such a scenario, Manning said there would have to be "a better social contract" put in place to determine how information is shared and accessed.

"One of the things about distributed or decentralized identification is that through encryption you're able to sort of check the box yourself, instead of having to depend on the company to provide you with a check box or an accept here, you're making that decision from a technical perspective," Manning said.

Manning, who works as a security consultant at Nym Technologies, a company that specializes in online privacy and security, was convicted of espionage and other charges at a court-martial in 2013 for leaking a trove of secret military files to online media publisher WikiLeaks.

She was sentenced to 35 years in prison, but was later released in 2017, when former U.S. President Barack Obama commuted her sentence.

Asked to what extent the environment has changed for whistleblowers today, Manning said, "We're at an interesting time because information is everywhere. We have more information than ever."

She added, "Countries and governments no longer seem to invest the same amount of time and effort in hiding information and keeping secrets. What countries seem to be doing now is they seem to be spending more time and energy spreading misinformation and disinformation."

Manning said the challenge for whistleblowers now is to sort through the information to understand what is verifiable and authentic.

"It's no longer secrecy versus transparency," she added.