I want to generate combinations in sequential range of the length 8-20 with the following characters:


How could I achieve this with kali's crunch wordlist generator tool?

I am trying to crack my own wifi password using crunch to test how secure it is, if there's a better method for cracking wifi passwords with generated wordlists I will accept this answer also if it works efficiently. (against random passwords for example: "DNTNYTJ$575dbMUYDfdwsv546u7bDF")

  • Wordlists are pretty ineffective against random passwords
    – wireghoul
    Feb 11, 2020 at 9:41
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    Your computer doesn't have enough space to even store all possible 20 character alpha-numeric passwords. This is quite literally impossible Feb 11, 2020 at 10:58
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    You're using the wrong approach, but by all means double down on this instead of googling how to do a brute force attack against a WiFi pcap
    – wireghoul
    Feb 11, 2020 at 11:15
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    If the password list is so long that you couldn't even store it on your computer, then what makes you think that you have the necessary CPU power to run through the list? Hint: when cracking passwords, storage space is the easy part. CPU resources are the thing that usually get in the way. Feb 11, 2020 at 12:58
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    send me a copy of the file once you get it created! /s
    – dandavis
    Feb 11, 2020 at 18:01

1 Answer 1


What you're asking is simply impossible. Not impossible as in you have a too slow computer - that can be solved with money. It's impossible as in physically impossible. You can't do what you ask.

Your charset has 83 characters. There's 83^20 20-character strings that can be formed from this. That's about 2.5*10^38, or incidentally approximately 2^127.5.

If you create one billion (10^9) 20-character strings per second, you'll spend over 10^20 years generating the 20-character strings. And you haven't yet started your 19-character strings - which is not a trivial problem either.

The universe is 10^10 years old. So generating the 20-character strings, if you have extremely fast storage, able to swallow 20 billion bytes per second, it would still take 10^10 times longer than the current age of the universe.

For those 10^20 years, you're filling a 10TB hard drive every 8 minutes. Currently they cost around 250USD a piece, so just storing this (if hard drives were that fast...) would cost you in the neighbourhood of 450000USD - per day. You'd probably call Seagate or someone and ask for a good bulk rate at that point, of course, explaining that you plan to keep on purchasing at that rate for as long as they are able to deliver.

When you're nearly finished, in around 10^19 years, you'll probably have some issues with the planning authorities - because the hard drives now equal the earth in mass, and lead to weird gravitational distortions.

83^20 is incidentally very close to 2^128, so pages such as this may be worth a read as well.

This is of course back of the napkin-math. It may be off by a order or three of magnitude - but that's irrelevant. The numbers show that your biggest worry is simply the heat death of the universe, not how fast your CPU is.

  • what an answer!
    – Runsis
    Sep 11, 2021 at 1:33

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