### public key
Note that any private key are a public key.

~~~

~~~

### private key




### cypher format

We use the `.cyp` file extension for the encrypted file.  A .cyp is nothing
else than a zip file containing the following shit.

1.  a `data.encrypted` containing the encrypted data
2.  a `meta_data.yml` file containing the meta data of the encrypted file
    *  symetric encryption algorithm
    *  mode
    *  encrypted symetric key
    *  hash of the encrypted data (always use full for validation)
3.  a 'signature' file with the signature of the `meta_data.yml` file