[tednoob]

I previously worked at Cryptify AB with Cryptify Call.

I think this article misses the point somewhat. This is not a backdoor, it is the entire point of the scheme. As I understood it CESG wants MIKEY-SAKKE primarily for use within the government or within companies working for the government.

For the network owner MIKEY-SAKKE is very convenient because it satisfies the criteria for Lawful interception[1] while also enabling end users to both authenticate and encrypt messages without actually talking to the network owner after the initial trust has been established. It works well as long as the user trust the network owner and you want to protect your users from external powers while maintaining the ability to decrypt any message in the network.

[1] https://en.wikipedia.org/wiki/Lawful_interception