The story I wrote about a backdoor in a TETRA radio standard used by police/military/critical infrastructure for radio communications, got lots of interest yesterday, with many people calling out ETSI for keeping the encryption algorithms secret. I decided to publish my entire interview with Brian Murgatroyd of ETSI so readers can see his justifications for doing this, as well as his responses to other things we discussed. I think you'll find some of his responses surprising
https://zetter.substack.com/p/interview-with-the-etsi-standards