During the third Democratic debate on Saturday night, Hillary Clinton called for a "Manhattan-like project" to break encrypted terrorist communications.
The project would "bring the government and the tech communities together" to find a way to give law enforcement access to encrypted messages, she said. It's something that some politicians and intelligence officials have wanted for awhile, especially after the recent terrorist attacks in Paris and San Bernardino, California. But is it feasible?
"There is no practical, real-world solution in which governments and law enforcement agencies are given a magical key into an encrypted service that only works for them and keeps the rest of our information safe from hackers or data thieves," Rafael Laguna, CEO of cloud services company Open-Xchange, told NBC News.
"The fact of the matter is simple: When you allow any kind of key or back door into encryption, you open the door for potentially anyone to walk through," he added. "Any suggestion that there can be a compromise that allows government to do this without undermining how encryption safeguards our privacy is pure politicking."
With encryption, the sender transmits a message that can only be decoded if the person or device receiving it has the key — anyone who intercepts it won't be able to understand it. There are a lot of different types of encryption, but the basic principle allows for tech companies like Apple to keep their users' information private.
Clinton didn't elaborate on how the "Manhattan-like project" — a reference to the secret U.S.-led effort in the 1940s to develop the first nuclear weapons — would find a way to only let law enforcement gain access to encrypted communications.
"It doesn't do anybody any good if terrorists can move toward encrypted communication that no law enforcement agency can break into before or after," she told ABC News' Martha Raddatz. "There must be some way. I don't know enough about the technology, Martha, to be able to say what it is, but I have a lot of confidence in our tech experts."
Many experts, such as the people in charge of Google, Facebook and other tech firms, don't think it's possible.
British Parliament recently proposed a bill that would let intelligence officials gain access to encrypted communications. In response, Apple wrote, "The creation of back doors and intercept capabilities would weaken the protections built into Apple products and endanger all our customers."
"A key left under the doormat would not just be there for the good guys," the company said. "The bad guys would find it too."
Anton Chuvakin, a research VP at Gartner's GTP Security and Risk Management group, agreed. He called Clinton's plan "absolutely implausible."
"Since encryption is derived from math, can you create a math puzzle that only 'a good guy' can solve?" Chuvakin told NBC News.
Still, many public figures, including California Sen. Dianne Feinstein and FBI Director James Comey, have implored Silicon Valley to find a way to make it happen.