I am sure there is a 12 year old Chinese kid working on the problem of encryption and one day they have to go to a new method. I know people have accountability and transparency issues and those are valid.
The biggest problem I see with encryption comes from a Justice System standpoint.
Simply said, persons who know they are on secure/encrypted channels are too often using the talkgroups and channels like they do on the CB and FRS radios where everything goes. Unfortunately, there are radio recorders on most systems and most if not all of those transmissions can be ordered into the court process.
Radio discipline with encryption is apparently not being enforced in many agencies. In my radios, out of the 817 talkgroups I have programmed, I can hear all of them except two. There are 102 of which are encrypted. The conversations that I am hearing are very worrisome because if/when that radio traffic is subpoenaed someday, it is going to be bad day for someone.
If you would not tell your god-fearing 90 year old grandmother something for fear of offending her, then you should not say it over public airwaves. No matter whether they are secured/encrypted or not.
When our channels for my agency finally put in the radios, I am going to continue to warn my personnel that there is nothing that is truly secure/encrypted. EVER.
And yes, I said 817, but you have to remember that as a deployable asset we have nine different systems in the radio right now.