The U.S. Department of Energy (DOE) seems to be very excited about the potential of a quantum Internet:
One of the hallmarks of quantum transmissions is that they are exceedingly difficult to eavesdrop on as information passes between locations. Scientists plan to use that trait to make virtually unhackable networks. Early adopters could include industries such as banking and health services, with applications for national security and aircraft communications. Eventually, the use of quantum networking technology in mobile phones could have broad impacts on the lives of individuals around the world. […] the quantum internet could become a secure communications network and have a profound impact on areas critical to science, industry, and national security.
So quantum transmissions would reveal if they were read in transit before the intended recipient, which would preclude MitM attacks. But so does TLS, and even though MitM attacks against TLS are possible, the vast majority of attacks are conducted not against data in transit, but against data at rest, OS and hardware vulnerabilities, and most commonly (between 80% and 98%, depending on which statistics you look at), via social engineering. I’ve looked at several cybersecurity stats, and the bottom line is that the vast majority of attacks are due to human error.
I’m trying to understand the excitement about the quantum Internet, and the reasons for the investments going into it.
Could quantum-secure transmissions help in any way mitigate the types of cyberattacks we’ve been seeing in the past 10 years, and which are likely to continue? "Early adopters could include industries such as banking" – how much has banking been affected by insecure Internet links (rather than hosts or persons)?
Or does the press release completely gloss over something else – that quantum computers (rather than the quantum Internet) would be able to break current public key crypotography, hence a quantum Internet would be useful to prevent those future attacks? Is that it, and a case of a vague press release, or am I neglecting something else?
In any case, I’m failing to understand how "the use of quantum networking technology in mobile phones could have broad impacts on the lives of individuals around the world". The vast majority of mobile phone users are completely oblivious to the security of their communications, and they wouldn’t behave any differently if they thought their communications were completely secure.