3 ms·
You'd need to cleverly narrow down the definition of "encrypted" you're operating under. The broad definition allows me to take your message and essentially tur
by jerf 5y ago
You'd need to cleverly narrow down the definition of "encrypted" you're operating under. The broad definition allows me to take your message and essentially turn it into any sequence of bits of sufficient length, and there's no way for you to then layer any further restrictions on top of that sequence because of the near-arbitrary power I have in selecting my encryption scheme. You'd need to reduce that power in some way to then create even a subset of messages that could survive the encryption.
Such a result would probably be of no practical use but it could be interesting in a recreational mathematics sort of way.
- bsedlm 5y ago> You'd need to cleverly narrow down the definition of "encrypted" you're operating under. absolutely. I suppose I should have explained that I'm thinking of "practical key-based symmetric(?) encryption", i.e. ecryption which hinges on a key which gets "expanded" by some clever (and aribtrary) algorithm into enough bits for any message; and which (it goes without saying) can be decrypted back exactly given a key and an algorithm (the same ones or at least very similar ones if symmetric). I'm not knowledgeable enough in cryptography to easily consider the assymetric case; but I don't think symmatric-asymmetrica changes things that much.
- jerf 5y agoIn that case you can encrypt your message by considering it as one big number, and creating a message long enough to encrypt to that many blocks. Inefficient in this particular case, but there are length-related attacks, so it's at least not crazily out of the domain of discourse. But I had to wait for you to qualify it that way, because if someone knows this is your plan, they can compensate with an "encryption" scheme that counters the approach.