i am going to retread the same ground, because its understandable if there is confusion about some of the points made which rest on some distinctions that are fairly obscure IMO.
there are two very different types of 'encrypted files' being discussed here.
type 1: 'a thing'
this is analagous to an A4 piece of paper with printed gobbledygook on it. this sheet of paper quacks like a duck, announcing in black and white that it is almost certainly an "encrypted file":
-----BEGIN CODED MESSAGE-----
Version: SecretData V1.2
-----END CODED MESSAGE-----
type 2: 'um...'
not so straightforward!
consider that any two ordinary blank sheets of A4 paper are never the same under a microscope. at that scale, none of them are uniformly white. instead, you will see an ocean of random patterns of tiny fibres with varying degrees of whiteness. in truth, every sheet of A4 paper is as unique as a snowflake.
now, suppose its possible to tweak a paper making machine so it can manufacture perfect blank A4 sheets of paper but also mathematically encode secret data into the apparently 'random patterns of tiny fibres' within ordinary paper.
then, there would be no process of analysis, no fancy machine in an NSA facility, no nobel laureate chemist, no OfficeWorks employee even, on the entire planet that could distinguish one of your encrypted sheets of A4 paper from an ordinary one.
at this point, which blank sheets of paper might contain hidden information? every single blank A4 page inside every office or home. all of them.
THIS IS THE MOST IMPORTANT POINT:
whilst you could hand the NSA one of your special encrypted blank A4 sheets and easily make 99.99% sure it would be impossible for them to decrypt it within your lifetime, it would actually be 100% impossible for them to know you didnt just hand them an ordinary sheet of paper until they did so!
when it comes to encryption stored in digital form on computers, type 1 and type 2 are 100% real.
examples of type 1: a zip file with a password, an email or word document containing a block of alphanumeric gobbledygook, a garbled end-to-end message.
examples of type 2: an audio recording of noise, the random '1' and '0's in the unused space on a hard drive
in the case of type 1, you *might* be tempted to argue that suspects should be compelled to produce passwords when a strong circumstantial case can be made that an ostensible 'encrypted file' exists.
in the case of type 2, it is all but impossible to make a strong case that an ostensible 'encrypted file' exists at all. moreover, it is 100% IMPOSSIBLE for any person to prove their hard drive contains no encrypted data.
TL;DR re: this hopefully beat up news story — the notion of drafting any law that would make it possible to convict people of a crime on mere suspicion of guilt, but even worse, in specific instances where proof of innocence is impossible to produce, is inconceivably daft.
- Nich... likes this