Struct ChaCha20Poly1305Cipher 

pub struct ChaCha20Poly1305Cipher { /* private fields */ }

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

impl ChaCha20Poly1305Cipher

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);

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)?;

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[..]);

Trait Implementations

impl Debug for ChaCha20Poly1305Cipher

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.