A (short?) comment on length #6
Description
I am not entirely sure what you are trying to achieve with the approximate length. You would need to have a lot of extra bits, well beyond the block size of a block cipher) to make it hard to guess language.
Consider an attacker who knows (through external sources) that a message communicated is in response to a sneeze. The number of bytes in
- Salud
- Bless you
- Gesundheit
- Egeszségedre
don't quite illustrate the point, as all of them would fit in a single block. But with longer texts, the distinctions would matter. After all, The Spanish is five bytes and the Hungarian is 12 or 13 bytes (depending on precisely how the é is encoded.)
Typically, cryptographic notions of secrecy don't include attempting to conceal anything about the length of the plaintext because it is hard to do. So I'd like to know what you are trying to prevent by attempting such a thing.