cloak-encryption 0.1.1
File and message encryption program

# Cloak Encryption

*A file and message encryptor with strong anonymity*

* **ChaCha20-Poly1305** stream cipher with authentication
* **Argon2** secures shorter passwords against cracking
* **Curve25519** public key encrypt & sign with [SSH](https://medium.com/risan/upgrade-your-ssh-key-to-ed25519-c6e8d60d3c54) and [Age](https://age-encryption.org/) keys

## Anonymity, privacy and authenticity

The encrypted archive looks exactly like random data, providing **deniability**. Every byte is protected so that not only is reading prevented but **authenticity** is also verified, protecting your data against any outsiders, and files may also be **signed** if necessary.

Other encryption tools add unencrypted headers revealing the recipients and other metadata. Cloak was created to address this very problem, to stop *all* information leakage.

A Cloaked message looks like this:
```
UMtgDS4BzWHx-1zPfKFPpyUnLfHzlUIO04bF35y4tN4VUcXqGuJDhYftvs6fpQ
```

## Try it!

If you are on Windows, install [Python](https://www.python.org/downloads/) first, otherwise you should be all set to install Cloak:
```
pip install cloak-encryption
```

Run cloak decryption and copy & paste the message above to see what it says (*wide-open* file, no passphrase required):

```
cloak dec
```

## File I/O speeds matching the fastest SSDs

<img src="https://github.com/cloak-encryption/cloak/blob/master/docs/benchmark.webp?raw=true" width="600" alt="Benchmark results. Cloak up to 4 GB/s.">

Cloak is the fastest of all the popular tools in both encryption (blue) and decryption (red).

Program|Lang|Algorithms|Operation
|---|---|---|---|
Cloak | Python | chacha20‑poly1305 sha512‑ed25519 | encrypt with auth and signature
Age | Go | chacha20-poly1305 | encrypt with auth
Rage | Rust | chacha20-poly1305 | encrypt with auth
OpenSSL | C | aes256-ctr (hw accelerated) | encrypt only
GPG | C | aes128-cfb, deflate | encrypt with auth and compression
sha512sum | C | sha512 | checksum only (for reference)

## A few interesting features

Files of any size may be attached to messages without the use of external tools, and without revealing any metadata such as modification times or usernames.

A completely different ciphertext is produced each time, usually of different size, even if the message and the key are exactly the same. Other crypto tools cannot do this.

Cloaked messages are much shorter than with other cryptosystems, accomplished by some ingenious engineering.

A key insight is that a receiver can *blindly* attempt to decrypt a file with many different keys and parameters until he finds a combination that authenticates successfully. This saves valuable space on short messages and improves security because no plain text headers are needed.

## Additional reading

* [Cloak Format Specification](https://github.com/cloak-encryption/cloak/blob/master/docs/Specification.md)
* [The PGP Problem](https://latacora.micro.blog/2019/07/16/the-pgp-problem.html)

Cloak is in an early development phase, so you are encouraged to try it but avoid using it on any valuable data just yet. We are looking for interested developers and the specification itself is still open to changes, no compatibility guarantees for current users.