Random hash in Python

What is the easiest way to generate a random hash (MD5) in Python?

4

10 Answers

A md5-hash is just a 128-bit value, so if you want a random one:

import random
hash = random.getrandbits(128)
print("hash value: %032x" % hash)

I don't really see the point, though. Maybe you should elaborate why you need this...

6

I think what you are looking for is a universal unique identifier.Then the module UUID in python is what you are looking for.

import uuid
uuid.uuid4().hex

UUID4 gives you a random unique identifier that has the same length as a md5 sum. Hex will represent is as an hex string instead of returning a uuid object.

The secrets module was added in Python 3.6+. It provides cryptographically secure random values with a single call. The functions take an optional nbytes argument, default is 32 (bytes * 8 bits = 256-bit tokens). MD5 has 128-bit hashes, so provide 16 for "MD5-like" tokens.

>>> import secrets
>>> secrets.token_hex(nbytes=16)
'17adbcf543e851aa9216acc9d7206b96'
>>> secrets.token_urlsafe(16)
'X7NYIolv893DXLunTzeTIQ'
>>> secrets.token_bytes(128 // 8)
b'\x0b\xdcA\xc0.\x0e\x87\x9b`\x93\\Ev\x1a|u'

0

This works for both python 2.x and 3.x

import os
import binascii
print(binascii.hexlify(os.urandom(16)))
'4a4d443679ed46f7514ad6dbe3733c3d'

3

Yet another approach. You won't have to format an int to get it.

import random
import string
def random_string(length): pool = string.letters + string.digits return ''.join(random.choice(pool) for i in xrange(length))

Gives you flexibility on the length of the string.

>>> random_string(64)
'XTgDkdxHK7seEbNDDUim9gUBFiheRLRgg7HyP18j6BZU5Sa7AXiCHP1NEIxuL2s0'

3

Another approach to this specific question:

import random, string
def random_md5like_hash(): available_chars= string.hexdigits[:16] return ''.join( random.choice(available_chars) for dummy in xrange(32))

I'm not saying it's faster or preferable to any other answer; just that it's another approach :)

import uuid
from md5 import md5
print md5(str(uuid.uuid4())).hexdigest()

import os, hashlib
hashlib.md5(os.urandom(32)).hexdigest()

The most proper way is to use random module

import random
format(random.getrandbits(128), 'x')

Using secrets is an overkill. It generates cryptographically strong randomness sacrifying performance.

All responses that suggest using UUID are intrinsically wrong because UUID (even UUID4) are not totally random. At least they include fixed version number that never changes.

import uuid
>>> uuid.uuid4()
UUID('8a107d39-bb30-4843-8607-ce9e480c8339')
>>> uuid.uuid4()
UUID('4ed324e8-08f9-4ea5-bc0c-8a9ad53e2df6')

All MD5s containing something other than 4 at 13th position from the left will be unreachable this way.

from hashlib import md5
plaintext = input('Enter the plaintext data to be hashed: ') # Must be a string, doesn't need to have utf-8 encoding
ciphertext = md5(plaintext.encode('utf-8')).hexdigest()
print(ciphertext)

It should also be noted that MD5 is a very weak hash function, also collisions have been found (two different plaintext values result in the same hash) Just use a random value for plaintext.

2

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