Project Lazarus

Project Lazarus is a rock solid encryption-suit.

Architecture:

The Key Scheduler

We take in a password and a nonce and hash them to get the seed for our key scheduler. The key scheduler takes this seed and
a) uses it to initialise an Eliptic-Curvce-Based RNG, which will later give us our eccState
b) hashes it using SHA3_256 to give us our hashState
every step the key scheduler performs a step operation on the EC, which gives us ou new eccState and hashes the old hashState together with this eccState to give us our next hashState. To generate a key from the state, the state is multiplied with a large number, then modulated. Finally it is (in most cases) hashed again with SHAKE_256 to allow for variable-length keys.

The Alpha Layer (AES)

In the Alpha-Layer we take our plaintext and encrypt it using a key and an iv both generated by our key scheduler.

The Psi Layer (HMAC)

In the Psi-Layer we generate an HMAC of the Alpha-Ciphertext using two keys taken from our key scheduler.

The Omega Layer (ChaCha20)

In the Omega-Layer we encrypt the Psi-Ciphertext using salsa2020, which we apply in cbc, in order to prevent any patterns to remain in the final ciphertext. (We also encrypt the HMAC this way; just to be sure). The key and iv for ChaCha20 and the iv for cbc are given to use by our fancy key scheduler.

Optionally a GZIP based compression can be applied.

The dark secret:

Look into bethany.py