I am using `gpg` to make encrypt a tar.gz.

- My first try uses `--verbose --symmetric` and then the decryption is done with `--verbose --decrypt`. The `--verbose` shows that encryption was done with `CAST5` and then the decryption uses `CAST5`.
  - i check all the file contents as a sanity check
- My second try uses `--verbose --cipher-algo AES256 --symmetric`. But I don't change the decrypt command... but somehow it knows to use `AES256`.
  - i check all the file contents as a sanity check

**how does gpg know which cipher is needed (in this case `AES256` instead of the default `CAST5`?**

p.s. Does `gpg` embed what cipher algorithm was used, yes/no? wouldn't it be "better" to not tell anyone what encryption type was used?