Note Ciphertexts

Encrypting a note plaintext involves the following steps:

1. Derive Ephemeral Secret Key: Use decaf377-ka to derive an ephemeral secret key esk.

2. Derive Diversified Public Key: Generate a diversified public key from the secret key epk.

3. Shared Secret Derivation: Perform a secure Diffie-Hellman key exchange to derive the shared secret between the sender and recipient.

4. Symmetric Key Generation: Generate a symmetric ChaCha20-Poly1305 payload key from the shared secret and ephemeral public key.

5. Encryption: Encrypt with note plaintext, represented as a vector of bytes, using the ChaCha20-Poly1305 encryption algorithm.

6. Construct the encrypted note ciphertext object.

The note ciphertext is 176 bytes in length.