Struct ChaCha20Poly1305Cipher

Source

pub struct ChaCha20Poly1305Cipher { /* private fields */ }

Expand description

ChaCha20-Poly1305 AEAD cipher for quantum-resistant symmetric encryption

This struct provides authenticated encryption with associated data using the ChaCha20 stream cipher for encryption and Poly1305 for authentication.

ChaCha20-Poly1305 is considered quantum-resistant because:

It relies on symmetric cryptography rather than mathematical problems
ChaCha20 uses a 256-bit key with a large keyspace (2^256)
Quantum attacks on symmetric ciphers require approximately 2^(n/2) operations
This means ~2^128 operations for ChaCha20, which is still computationally infeasible

Implementations§

Source §

impl ChaCha20Poly1305Cipher

Source

pub fn new(key: &SymmetricKey) -> ChaCha20Poly1305Cipher

Create a new ChaCha20-Poly1305 cipher with the given key

§Arguments

key - The symmetric encryption key

§Example

use saorsa_pqc::symmetric::{ChaCha20Poly1305Cipher, SymmetricKey};

let key = SymmetricKey::generate();
let cipher = ChaCha20Poly1305Cipher::new(&key);

Source

pub fn encrypt( &self, plaintext: &[u8], associated_data: Option<&[u8]>, ) -> Result<(Vec<u8>, [u8; 12]), SymmetricError>

Encrypt plaintext data

This method encrypts the provided plaintext and returns the ciphertext along with the nonce used for encryption. The nonce is randomly generated for each encryption operation.

§Arguments

plaintext - The data to encrypt
associated_data - Optional associated data that is authenticated but not encrypted

§Returns

A tuple containing the ciphertext and the nonce used for encryption

§Errors

Returns SymmetricError::EncryptionFailed if encryption fails

§Example

use saorsa_pqc::symmetric::{ChaCha20Poly1305Cipher, SymmetricKey};

let key = SymmetricKey::generate();
let cipher = ChaCha20Poly1305Cipher::new(&key);

let plaintext = b"Secret message";
let (ciphertext, nonce) = cipher.encrypt(plaintext, None)?;

Source

pub fn decrypt( &self, ciphertext: &[u8], nonce: &[u8; 12], associated_data: Option<&[u8]>, ) -> Result<Vec<u8>, SymmetricError>

Decrypt ciphertext data

This method decrypts the provided ciphertext using the given nonce.

§Arguments

ciphertext - The encrypted data to decrypt
nonce - The nonce that was used during encryption
associated_data - Optional associated data that was authenticated during encryption

§Returns

The decrypted plaintext

§Errors

Returns SymmetricError::DecryptionFailed if decryption or authentication fails

§Example

use saorsa_pqc::symmetric::{ChaCha20Poly1305Cipher, SymmetricKey};

let key = SymmetricKey::generate();
let cipher = ChaCha20Poly1305Cipher::new(&key);

let plaintext = b"Secret message";
let (ciphertext, nonce) = cipher.encrypt(plaintext, None)?;
let decrypted = cipher.decrypt(&ciphertext, &nonce, None)?;
assert_eq!(plaintext, &decrypted[..]);