Safew加密原理深度解析：从AES-256到后量子密码学的技术演进

class AES256Encryptor:
    def __init__(self, key):
        if len(key) != 32:  # 256位 = 32字节
            raise ValueError("Key must be 256 bits (32 bytes)")
        self.key = key
        self.rounds = 14  # AES-256轮数
        
    def encrypt_block(self, plaintext):
        """加密单个128位数据块"""
        state = self.bytes_to_matrix(plaintext)
        
        # 初始轮密钥加
        state = self.add_round_key(state, self.round_keys[0])
        
        # 主轮循环
        for round in range(1, self.rounds):
            state = self.sub_bytes(state)      # 字节替换
            state = self.shift_rows(state)     # 行移位
            state = self.mix_columns(state)    # 列混淆
            state = self.add_round_key(state, self.round_keys[round])
        
        # 最终轮（省略列混淆）
        state = self.sub_bytes(state)
        state = self.shift_rows(state)
        state = self.add_round_key(state, self.round_keys[self.rounds])
        
        return self.matrix_to_bytes(state)

class RSAKeyGenerator:
    def __init__(self, key_size=2048):
        self.key_size = key_size
        
    def generate_key_pair(self):
        """生成RSA密钥对"""
        # 生成大素数
        p = self.generate_large_prime(self.key_size // 2)
        q = self.generate_large_prime(self.key_size // 2)
        
        n = p * q  # 模数
        phi = (p - 1) * (q - 1)  # 欧拉函数
        
        # 选择公钥指数
        e = 65537  # 常见选择
        
        # 计算私钥指数
        d = self.modular_inverse(e, phi)
        
        return {
            'public_key': (e, n),
            'private_key': (d, n),
            'parameters': (p, q, phi)
        }
    
    def encrypt(self, message, public_key):
        """RSA加密"""
        e, n = public_key
        # 使用快速幂算法
        return pow(message, e, n)

class SessionKeyManager:
    def __init__(self):
        self.master_key = None
        self.session_keys = {}
        
    def derive_session_key(self, session_id, ephemeral_secret):
        """派生会话密钥"""
        # 使用HKDF算法
        salt = os.urandom(32)
        info = f"session_{session_id}".encode()
        
        # HKDF扩展过程
        prk = HMAC.new(salt, ephemeral_secret, SHA256).digest()
        session_key = HMAC.new(prk, info, SHA256).digest()
        
        self.session_keys[session_id] = session_key
        return session_key
    
    def encrypt_message(self, session_id, message):
        """使用会话密钥加密消息"""
        session_key = self.session_keys[session_id]
        nonce = os.urandom(12)  # GCM模式需要12字节随机数
        
        cipher = AES.new(session_key, AES.MODE_GCM, nonce=nonce)
        ciphertext, tag = cipher.encrypt_and_digest(message)
        
        return nonce + ciphertext + tag

class KyberEncryptor:
    """CRYSTALS-Kyber后量子加密算法实现"""
    
    def keygen(self):
        """密钥生成"""
        # 生成随机矩阵A
        A = self.generate_uniform_matrix()
        
        # 生成错误向量s, e
        s = self.sample_centered_binomial()
        e = self.sample_centered_binomial()
        
        # 计算t = A*s + e
        t = self.matrix_vector_multiply(A, s) + e
        
        return (t, A), s  # 公钥，私钥
    
    def encrypt(self, public_key, message):
        """加密"""
        t, A = public_key
        
        r = self.sample_centered_binomial()
        e1 = self.sample_centered_binomial()
        e2 = self.sample_centered_binomial()
        
        u = A.T @ r + e1
        v = t @ r + e2 + self.encode_message(message)
        
        return (u, v)

class DoubleRatchet:
    def __init__(self):
        self.root_chain = RootChain()
        self.sending_chain = SendingChain()
        self.receiving_chain = ReceivingChain()
        
    def ratchet_encrypt(self, message):
        """棘轮加密"""
        # 生成新的临时密钥对
        new_dh = self.generate_dh_key()
        
        # 根链更新
        root_key = self.root_chain.step(self.dh_key, new_dh)
        
        # 发送链更新
        message_key = self.sending_chain.step(root_key)
        
        # 加密消息
        ciphertext = self.encrypt_with_key(message, message_key)
        
        return {
            'dh_public': new_dh.public_key(),
            'ciphertext': ciphertext,
            'sequence': self.sequence_number
        }

// AES-NI指令集优化示例
void aesni_encrypt(const uint8_t* plaintext, uint8_t* ciphertext, 
                   const AES_KEY* key) {
    __m128i state = _mm_loadu_si128((const __m128i*)plaintext);
    
    // 初始轮密钥加
    state = _mm_xor_si128(state, key->rd_key[0]);
    
    // 主轮循环（使用AESNI指令）
    for (int i = 1; i < key->rounds; i++) {
        state = _mm_aesenc_si128(state, key->rd_key[i]);
    }
    
    // 最终轮
    state = _mm_aesenclast_si128(state, key->rd_key[key->rounds]);
    
    _mm_storeu_si128((__m128i*)ciphertext, state);
}

def constant_time_compare(a, b):
    """常数时间比较，防止时序攻击"""
    if len(a) != len(b):
        return False
    
    result = 0
    for x, y in zip(a, b):
        result |= x ^ y
        
    return result == 0

class ZKIdentity:
    def prove_knowledge(self, secret, public_info):
        """生成零知识证明"""
        # 设置可信设置
        crs = self.trusted_setup()
        
        # 生成证明
        proof = self.generate_proof(secret, public_info, crs)
        
        return proof
    
    def verify_proof(self, proof, public_info):
        """验证证明"""
        return self.verify(proof, public_info, self.crs)

class HomomorphicEncryption:
    def encrypt(self, value):
        """Paillier同态加密"""
        n = self.public_key
        g = n + 1  # 简化计算
        
        r = random.randint(1, n-1)
        ciphertext = (pow(g, value, n*n) * pow(r, n, n*n)) % (n*n)
        
        return ciphertext
    
    def homomorphic_add(self, c1, c2):
        """同态加法"""
        return (c1 * c2) % (self.public_key * self.public_key)