What if a hacker plants "secret encrypted documents" on your computer, and then the government demands that you produce a key for them? This situation has allegedly already played out with child porn[0], and planting drugs is not unheard of by unscrupulous police officers[1]. Essentially, you're back at the issue GP describes - we don't trust government employees with this much power over our lives.
[0] - https://www.nytimes.com/2016/12/09/world/europe/vladimir-put...
[1] - https://www.innocenceproject.org/leaked-documents-show-alaba...
Personally, I find that suggestion repugnant.
We also require people to document their finances to accurately tax them. You're presumed 'guilty until proven innocent' in the sense that you're taxed on income unless you can document that it's untaxable(a business expense). There are penalties for failing to document things. What's wrong with requiring you to document your private keys, along with your receipts?
If you sell apples under the name "Loving Apples", you have to pay your state government to register that name. You can be fined for not registering your name, and your bank or other financial provider will want to see the government approval document. You could have the government maintain a central registry of all private keys, and make it a crime to encrypt a document with a key not documented in a state agency.
If you receive a document that is encrypted, you may be further required to tell the government who gave it to you, to ensure compliance with the encryption law; similar to how giving someone money requires you to tell the government about the transaction for compliance with tax law.
Which direction of the implication you take is a matter of preference. People who agree with giving the government full power(and trust them not to abuse it) or who agree with not giving the government any of this power are both logically consistent with my argument.
I'm only attempting to rule out people who are okay with all of the existing documentation requirements, but balk at documenting their encryption keys.
If your personal escrow key is government mandated, and well-protected, that prevents the issue of you forgetting passwords (Estonia already has something like this). It also fully ensures that the government accessing escrowed keys requires you being informed.
I still don't support this plan, but it is the best thing I've seen.
That's exactly what my (UK) government has done.
It's a horrific idea.
That is a lot more out in the open than a "back door". When the government bashes through the door at least it's in plain site and the house owner knows it's happening. But with encryption how would you know if the government has used their access?