import?pyDes
data?=?"DES?Algorithm?Implementation"
k?=?pyDes.des("DESCRYPT",?pyDes.CBC,?"\0\0\0\0\0\0\0\0",?pad=None,?padmode=pyDes.PAD_PKCS5)
d?=?k.encrypt(data)
print?"Encrypted:?%r"?%?d
print?"Decrypted:?%r"?%?k.decrypt(d)
assert?k.decrypt(d)?==?data

它調(diào)用變量 padmode ，它根據(jù)DES算法實(shí)現(xiàn)提取所有包，并以指定的方式進(jìn)行加密和解密.

輸出

您可以看到以下輸出作為上面和下面給出的代碼的結(jié)果;

非對(duì)稱加密

它也被稱為公鑰加密.它以對(duì)稱加密的相反方式工作.這意味著它需要兩個(gè)密鑰:一個(gè)用于加密，另一個(gè)用于解密.公鑰用于加密，私鑰用于解密.

缺點(diǎn)

由于其密鑰長(zhǎng)度，它的加密速度較低.
密鑰管理至關(guān)重要.

以下Python中的程序代碼說明了使用RSA算法進(jìn)行非對(duì)稱加密的工作及其實(shí)現(xiàn) :

from?Crypto?import?Random
from?Crypto.PublicKey?import?RSA
import?base64
def?generate_keys():
???#?key?length?must?be?a?multiple?of?256?and?>=?1024
???modulus_length?=?256*4
???privatekey?=?RSA.generate(modulus_length,?Random.new().read)
???publickey?=?privatekey.publickey()
???return?privatekey,?publickey
def?encrypt_message(a_message?,?publickey):
???encrypted_msg?=?publickey.encrypt(a_message,?32)[0]
???encoded_encrypted_msg?=?base64.b64encode(encrypted_msg)
???return?encoded_encrypted_msg
def?decrypt_message(encoded_encrypted_msg,?privatekey):
???decoded_encrypted_msg?=?base64.b64decode(encoded_encrypted_msg)
???decoded_decrypted_msg?=?privatekey.decrypt(decoded_encrypted_msg)
???return?decoded_decrypted_msg
a_message?=?"This?is?the?illustration?of?RSA?algorithm?of?asymmetric?cryptography"
privatekey?,?publickey?=?generate_keys()
encrypted_msg?=?encrypt_message(a_message?,?publickey)
decrypted_msg?=?decrypt_message(encrypted_msg,?privatekey)
print?"%s?-?(%d)"?%?(privatekey.exportKey()?,?len(privatekey.exportKey()))
print?"%s?-?(%d)"?%?(publickey.exportKey()?,?len(publickey.exportKey()))
print?"?Original?content:?%s?-?(%d)"?%?(a_message,?len(a_message))
print?"Encrypted?message:?%s?-?(%d)"?%?(encrypted_msg,?len(encrypted_msg))
print?"Decrypted?message:?%s?-?(%d)"?%?(decrypted_msg,?len(decrypted_msg))