"The UK may also be concerned about the legality of their own demand to access encrypted messages. Riana Pfefferkorn, a cryptography policy fellow at Stanford University, said she sees a legal battle coming if the UK continues to force the issue, but she doesn't necessarily think the UK wants that fight.
If courts determine that the Investigatory Powers Act is too broad, the public defeat in their fight against encryption would be a lot for the UK to overcome. Instead, Pfefferkorn said the government might just try hacking for the information they want, a power that the IP Act also allows.
"There are other avenues they can take to try to achieve the same end," she said."