Paranoid

Is what you’re called

If cellphone cells

Have you appalled :

Strangely,

If a stranger called

You weren’t

Paranoid at all.

Security Gap Allows Eavesdropping on Mobile Phone Calls
Ruhr-Universitaet-Bochum via Phys.org / August 12, 2020

Calls via the LTE mobile network, also known as 4G, are encrypted and should therefore be tap-proof. However, researchers from the Horst Görtz Institute for IT Security (HGI) at Ruhr-Universität Bochum have shown that this is not always the case.

They were able to decrypt the contents of telephone calls if they were in the same radio cell as their target, whose mobile phone they then called immediately following the call they wanted to intercept. They exploit a flaw that some manufacturers had made in implementing the base stations.

…

Reusing keys results in security gap

The vulnerability affects Voice over LTE, the telephone standard used for almost all mobile phone calls if they are not made via special messenger services. When two people call each other, a key is generated to encrypt the conversation.

“The problem was that the same key was also reused for other calls,” says David Rupprecht. Accordingly, if an attacker called one of the two people shortly after their conversation and recorded the encrypted traffic from the same cell, he or she would get the same key that secured the previous conversation.

“The attacker has to engage the victim in a conversation,” explains David Rupprecht. “The longer the attacker talked to the victim, the more content of the previous conversation he or she was able to decrypt.” For example, if attacker and victim spoke for five minutes, the attacker could later decode five minutes of the previous conversation.

…

By now, the manufacturers and mobile phone providers have updated the software of the base stations to fix the problem….

Still, it can’t be ruled out that there are radio cells somewhere in the world where the vulnerability occurs.