Re: What are the chances of this encrytion being broken?

On 23/03/2025 04:14, hal@invalid.com wrote:

What are the chances that the encrypted text in this message could be
broken?

The chance that it could be broken? Not enough information to say with any accuracy. Might be easy, might be close to impossible. It's long enough that a huge quantum computer given a very long time to do it could in theory do it, so it's not totally absolutely impossible.
The chances that someone will actually bother to break it? Close to zero.

No one knows what program made the file.

Alice knows. So does Bob. So do their computers. Their software suppliers may have hints. Und so weiter.
We usually assume that the program/cipher is known because, if kept secret, if the secret is revealed once it is revealed for all instances (Kerckhoff's principle).

It's 256 bit encryption.

But is it _good_ 256-bit encryption? If it's home-grown it isn't good (Schneier's law).
Then there is always lead pipe cryptanalysis...
https://xkcd.com/538/
Peter F