encryption is not ever to be considered impossible to break.
every encryption scheme has at least one way to be decrypted.
fidelity of information is one use of encryption, if you apply the solution and get garbage, something is wrong, somewhere.
occultation of information is another use, that is commonly abused by extending undue trust. under the proviso that encryption will eventually be broken, you cant trust encryption to keep a secret forever, but you can keep it secret, for long enough that it is no longer applicible to an attack,or slightly askew usecase, thus aggressive rotation of keys becomes desirable
> encryption is not ever to be considered impossible to break
One-time pads [0] are actually impossible to break, but they're pretty tricky to use: you must never ever reuse them, they must be truely random, and you need some way to share them between both parties (which isn't that easy since they need to be at least as large as all the data that you ever want to transmit).
[0]: https://en.wikipedia.org/wiki/One-time_pad
not trying to be obtuse, but there is at least one solution, the one used to decrypt.
if you know something about the content e.g. it is for russians, or americans.
you can use a frequency analysis to identify vowels. that goes for a simple substitution cypher that is relying on low frequency of usage[one time use] and does not keep it brief.
when you further substitute numbers for words, you gain more room for verbosity.
if you have high stakes, your message in the clear, should only be useful for a limited time, at the point that it is no longer actionable.
im very familiar with one time pads random, and keyed.
they are a little simple, you can use a triaxial scheme, or a tensor like scheme, for more leg room and more complexity.
depending on what you are doing it may be necessary, to not carry any pads, but to have access at some point, to agreed upon keys, in order to generate a pad on the spot. or even work in your head, if you have skill. e.g. jackdwlovemybigsphnxfqurtz as a weak example.
> not trying to be obtuse, but there is at least one solution, the one used to decrypt
Right, which is why I didn't quote that part :)
> you can use a frequency analysis to identify vowels.
That will help in many cases, but not against a properly-used one-time-pad.
> but to have access at some point, to agreed upon keys, in order to generate a pad on the spot
That's not really a one-time pad then, that's just a stream cipher. Which do work better than one-time pads in the vast majority of cases, aside from not being "perfectly" secure.