Common information security encryption algorithms and Python library source code examples

1. Common information security encryption algorithms

1.1. Symmetric encryption algorithm:

• AES (Advanced Encryption Standard): symmetric key encryption algorithm, widely used and safe and reliable.
• DES (Data Encryption Standard): symmetric key encryption algorithm, which has been replaced by AES, but is still used in some applications.
• 3DES (Triple Data Encryption Standard): An enhanced version of DES that improves security through multiple iterations of the DES algorithm.

1.2. Asymmetric encryption algorithm:

• RSA (Rivest-Shamir-Adleman): Asymmetric key encryption algorithm used for data encryption and digital signatures.
• ECC (Elliptic Curve Cryptography): An asymmetric encryption algorithm based on elliptic curves. It has a shorter key length at the same security level and is suitable for resource-constrained environments.
• DSA (Digital Signature Algorithm): an asymmetric encryption algorithm used for digital signatures.

1.3. Hash function:

• SHA-256 (Secure Hash Algorithm 256-bit): A commonly used hash function in the SHA-2 series, generating a 256-bit hash value.
• MD5 (Message Digest Algorithm 5): An older hash algorithm, but because it is susceptible to collision attacks, it is now mainly used to verify file integrity rather than for security purposes.

1.4. Message Authentication Code (MAC):

• HMAC (Keyed-Hash Message Authentication Code): A message authentication code algorithm that combines a hash function and a key to verify the integrity and authenticity of the message.

These are some common encryption algorithms that play an important role in protecting the confidentiality, integrity, and authenticity of data. Choosing the appropriate encryption algorithm depends on specific security needs, performance requirements, and available resources. In practical applications, multiple encryption algorithms are often used in combination to achieve stronger security.

2. Encryption algorithm Python library source code example

2.1. AES symmetric encryption algorithm (using cryptographylibrary)

from cryptography.fernet import Fernet

# 生成密钥
key = Fernet.generate_key()

# 创建加密器
cipher = Fernet(key)

# 加密数据
data = b"Hello, world!"
encrypted_data = cipher.encrypt(data)

# 解密数据
decrypted_data = cipher.decrypt(encrypted_data)

2.2. DES symmetric encryption algorithm (using pycryptodomelibrary)

from Crypto.Cipher import DES

# 生成密钥（长度必须为8字节）
key = b"secretkey"

# 创建加密器
cipher = DES.new(key, DES.MODE_ECB)

# 加密数据（长度必须为8字节的倍数）
data = b"Hello, world!"
padded_data = data + b"\x00" * (8 - (len(data) % 8))  # 填充数据
encrypted_data = cipher.encrypt(padded_data)

# 解密数据
decrypted_data = cipher.decrypt(encrypted_data).rstrip(b"\x00")  # 去除填充数据

2.3. Triple DES symmetric encryption algorithm (using pycryptodomelibrary)

from Crypto.Cipher import DES3

# 生成密钥
key = b"0123456789abcdef01234567"

# 创建加密器
cipher = DES3.new(key, DES3.MODE_ECB)

# 加密数据
data = b"Hello, world!"
encrypted_data = cipher.encrypt(data)

# 解密数据
decrypted_data = cipher.decrypt(encrypted_data)

2.4 RSA asymmetric encryption algorithm (using cryptographylibrary)

from cryptography.hazmat.primitives import serialization, hashes
from cryptography.hazmat.primitives.asymmetric import rsa, padding

# 生成RSA密钥对
private_key = rsa.generate_private_key(
    public_exponent=65537,
    key_size=2048
)
public_key = private_key.public_key()

# 加密数据
data = b"Hello, world!"
encrypted_data = public_key.encrypt(
    data,
    padding.OAEP(
        mgf=padding.MGF1(algorithm=hashes.SHA256()),
        algorithm=hashes.SHA256(),
        label=None
    )
)

# 解密数据
decrypted_data = private_key.decrypt(
    encrypted_data,
    padding.OAEP(
        mgf=padding.MGF1(algorithm=hashes.SHA256()),
        algorithm=hashes.SHA256(),
        label=None
    )
)

2.5. ECC asymmetric encryption algorithm (using cryptographylibrary)

from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.backends import default_backend

# 生成ECC密钥对
private_key = ec.generate_private_key(
    ec.SECP256R1(),  # 可替换为其他的椭圆曲线参数
    default_backend()
)
public_key = private_key.public_key()

# 加密数据
data = b"Hello, world!"
encrypted_data = public_key.encrypt(
    data,
    ec.ECIES(
        ec.ECDH(),
        default_backend()
    )
)

# 解密数据
decrypted_data = private_key.decrypt(
    encrypted_data,
    ec.ECIES(
        ec.ECDH(),
        default_backend()
    )
)

2.6 DSA asymmetric encryption algorithm (using cryptographylibrary)

from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import dsa
from cryptography.hazmat.backends import default_backend

# 生成DSA密钥对
private_key = dsa.generate_private_key(
    key_size=1024,
    backend=default_backend()
)
public_key = private_key.public_key()

# 加密数据（签名）
data = b"Hello, world!"
signature = private_key.sign(data, dsa.HASH_SHA256)

# 解密数据（验证签名）
try:
    public_key.verify(signature, data, dsa.HASH_SHA256)
    valid_signature = True
except InvalidSignature:
    valid_signature = False

2.7. SHA-256 hash function (using built-in hashliblibrary)

import hashlib

# 计算哈希值
data = b"Hello, world!"
hash_object = hashlib.sha256(data)
hash_value = hash_object.hexdigest()

2.8. HMAC message authentication code (using built-in hmaclibrary)

import hmac

# 计算HMAC
data = b"Hello, world!"
key = b"secret_key"
hmac_value = hmac.new(key, data, hashlib.sha256).digest()

These sample codes use some common encryption libraries and functions in Python to implement corresponding encryption algorithms. These sample codes are for demonstration purposes only. Appropriate adjustments and error handling should be made according to specific needs during actual use. In addition, to ensure security, make sure to use sufficiently strong keys and appropriate parameter configurations when using encryption algorithms.