Some of the most prominent cryptography and security researchers in U.S. academia have condemned the U.S. National Security Agency’s surveillance practices and called for change.

”Media reports since last June have revealed that the US government conducts domestic and international surveillance on a massive scale, that it engages in deliberate and covert weakening of Internet security standards, and that it pressures US technology companies to deploy backdoors and other data-collection features,” the researchers said in an open letter published Friday. “As leading members of the US cryptography and information-security research communities, we deplore these practices and urge that they be changed.”

The letter was signed by 53 people, most of them professors at top U.S. universities and research institutions. The list includes some of the biggest names in computer science, technology policy and cryptography like Hal Abelson, professor at the Massachusetts Institute of Technology and founding director of Creative Commons and the Free Software Foundation; Edward Felten, the director of the Center for Information Technology Policy at Princeton University and former chief technologist for the U.S. Federal Trade Commission; MIT professor Ronald Rivest, a pioneer of modern public-key cryptography and of one the creators of the widely used RSA encryption algorithm; and renowned cryptographer Bruce Schneier.

Dutch cryptographer Niels Ferguson is also on the list. Ferguson was one of the two Microsoft employees who in 2007 reported that the Dual_EC_DRBG pseudorandom number generator standardized by the U.S. National Institute of Standards and Technology had a potential backdoor. According to media reports based on documents leaked by former government contractor Edward Snowden, the NSA pushed this flawed random number generator as a standard as part of its efforts to defeat encryption.

”Inserting backdoors, sabotaging standards, and tapping commercial data-center links provide bad actors, foreign and domestic, opportunities to exploit the resulting vulnerabilities,” the letter said. The choice is not between allowing the NSA to spy or not, but between having a communications infrastructure that’s vulnerable to attack at its core and one that’s by default secure for all users, they said.

”Every country, including our own, must give intelligence and law-enforcement authorities the means to pursue terrorists and criminals, but we can do so without fundamentally undermining the security that enables commerce, entertainment, personal communication, and other aspects of 21st-century life,” the researchers said in the letter. “We urge the US government to reject society-wide surveillance and the subversion of security technology, to adopt state-of-the-art, privacy-preserving technology, and to ensure that new policies, guided by enunciated principles, support human rights, trustworthy commerce, and technical innovation.”

The letter also called for the U.S. government to subject all mass-surveillance activities to public scrutiny, saying that the threat they pose to privacy and democracy is evident, while the value they have in preventing terrorism is unclear. They noted that the five principles described on the reformgovernmentsurveillance.com website that was set up by AOL, Apple, Facebook, Google, LinkedIn, Microsoft, Twitter and Yahoo in response to the NSA surveillance revelations provide a good starting point for finding a way forward.

According to those principles, governments should, among other things, limit surveillance to specific, known users rather than collect Internet communications in bulk; set up an independent court review system that includes an adversarial process; allow companies to publish the number and nature of government demands for user information; and permit the transfer of data across borders, working with other governments to resolve conflicts of legislation governing lawful requests for data.

According to Matthew Green, a cryptography research professor at Johns Hopkins University in Baltimore and one of the people who signed the letter, the joint statement is indicative of the trust the NSA has lost among academics.

”Up until 2013 if you’d asked most US security researchers for their opinions on NSA, you would, of course, have heard a range of views,” Green said Saturday in a blog post. “But you also might have heard notes of (perhaps grudging) respect. This is because many of the NSA’s public activities have been obviously in everyone’s interest—helping to fund research and secure our information systems.”

Even when there was evidence of potential “unfair dealing” by the NSA, as in the case of Dual_EC_DRBG, most researchers dismissed the allegations as conspiracy theories, Green said. “We believed the NSA would stay between the lines. Putting backdoors into US information standards was possible, of course. But would they do it? We thought nobody would be that foolish. We were wrong.”

Green feels that NSA’s actions might have long-term implications for the society as a whole.

”Our economic and electronic security depend very much on the cooperation of academia, industry and private citizens,” he said. “The NSA’s actions have destroyed this trust. And ironically, that makes us all less safe.”