- Chacha20 from [rustcrypto streamciphers](https://github.com/RustCrypto/stream-ciphers)
- Blake2b from [rustcrypto hashes](https://github.com/RustCrypto/hashes/tree/master)
- turboshake KDF from [rustcrypto SHA3](https://github.com/RustCrypto/hashes/tree/master/sha3)
The security of lioness reduce to the security of the underlying stream cipher or
the hash function.
See the [paper](https://www.cl.cam.ac.uk/~rja14/Papers/bear-lion.pdf) for more information.
### How to use
Here is an example of how to use the `Lioness_blockcipher` create.
Use a 32-byte master key and encrypt or decrypt a block in place:
```rust
use lioness_blockcipher::{Lioness, MasterKey};
fn main() -> anyhow::Result<()> {
let mut key: MasterKey = [0x42; 32];
let cipher = Lioness::new(&key);
// Blocks must be at >32 bytes long
let mut block = b"this is a long plaintext block and must stay a secret".to_vec();
let original = block.clone();
cipher.encrypt_in_place(&mut block)?;
cipher.decrypt_in_place(&mut block)?;
assert_eq!(block, original);
Ok(())
}
```
Some notes:
- Encryption and decryption are both in-place for now.
- The block length need to be bigger than `32` bytes because Lioness splits the block into two where the left part is 32-byte, and the right part can't be empty. might support small blocks in the future, but for Sphinx use-case, this should work.
- If you need authenticity, make sure to prepend the plaintext with `k = 128-bits` zeros and check the zeros after decryption. This will be supported in the future... see [integrity example](./examples/integrity.rs)
