Detailed introduction to Python md5 and sha1 encryption algorithms

This article briefly introduces the concept and principle of the md5-level sha1 encryption algorithm, and analyzes it in the form of examplesPythonThe specific operating skills of using the hashlib module to implement the encryption function. Friends in need can refer to the following

If there is too much content encrypted by md5 and sha1, you can use it like this:

[python]  
m = hashlib.md5()  
m.update('a')  
m.update('b')  
s = m.hexdigest()  
#效果等于m = hashlib.md6('ab').hexd

MD5

The full name of MD5 is Message-Digest Algorithm 5 (information-Abstract algorithm) was developed in the early 1990s by Ronald L. Rivest of the MIT Laboratory for Computer Science and RSA Data Security Inc. It was developed from MD2, MD3 and MD4. It is an irreversible encryption algorithm. It is currently one of the most reliable encryption algorithms. No program that can reverse the operation has been developed. It can encrypt any string into a unique fixed-length string. code.

Features:

First of all, it is irreversible. There is no systematic way to know what the original text of the MD5 code is

Secondly, this code has high It is discrete and has no rules to follow. Even a small change in the original information will lead to a huge change in MD5. It can also be said that the generated MD5 code is unpredictable.

Finally, since this code is 128 bits long, the possibility of having the same MD5 code between any messages is very low and is generally considered impossible.

Use:

It is generally believed that MD5 code can uniquely represent the characteristics of the original information, and is usually used for encrypted storage of passwords, digital signatures, file integrity verification, etc.

SHA1

The full name of SHA1 is Secure Hash Algorithm (SecureHash algorithm), which is designed by NIST NSA Used with DSA, it generates a hash value of length 160 bits for inputs with a length less than 264, so it is more resistant to brute-force. SHA-1 is designed based on the same principles as MD4 and mimics this algorithm. SHA-1 is a national standard promulgated by the National Institute of Standards and Technology (NIST). It is the most widely used hashfunction algorithm and is currently the most advanced encryption technology used by government departments and private owners. Handling sensitive information. SHA-1 is based on MD5, which is based on MD4.

SHA-1 has 32 more ciphertext bits than MD5, so it is more secure. MD5 operates faster than SHA-1 for the same reason.

Usage example:

The hashlib module in Python is a library that specifically provides hash algorithms. It currently includes md5, sha1, sha224, sha256 , sha384, sha512, very simple and convenient to use. Usage is as follows:

import hashlib
hash_new = hashlib.sha1() #或hashlib.md5()
with open('driver.xml.tar.bz2','rb') as fp: #打开文件，一定要以二进制打开
  while True:
    data = fp.read() #读取文件块
    if not data: #直到读完文件
      break
    hash_new.update(data)
hash_value = hash_new.hexdigest() #生成40位(sha1)或32位(md5)的十六进制字符串
print hash_value

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