Enter a password:
This page estimates the entropy of a supplied password in the form using zxcvbn by Dropbox. Unlike traditional password meters, this is based on entropy and actual brute force cracking numbers.
According to https://tools.ietf.org/html/rfc4086#section-8.1, which is an RFC on best current practices for online security, passwords should contain at least 29-bits of security to thwart an online brute-force search with a login prompt.
However, when databases are compromised and leaked to the Internet, offline password cracking can work much faster than online brute force searches. The following are three actually implemented brute force searching speeds:
For offline password cracking security, passwords should have at a minimum of 80-bits of entropy, and for good safety margins, at least 88-bits of entropy.
The entropy of a supplied password is fed to each of these scenarios to see how long the password would last in a brute force search. Learn more about entropy at https://pthree.org/?p=3492/.
This password has approximately: -bits of entropy.
There is very likely not enough energy in the known universe to completely brute force 256-bits, let alone this password. To prove this to you, I'll defer to the laws of thermodynamics.
What does this mean? Unless your computer using energy from somewhere outside of our known universe, it is strongly implied that you cannot flip every bit in 256-bits to completeion.
Physics prevents it.
If you want to read more, see my blog post at https://pthree.org/2016/06/19/the-physics-of-brute-force/.
Thus, to 100% guarantee that this password is found, it would take:
|8 Nvidia GTX 1080 GPUs|
|The distributed.net cluster|
|The Bitcoin network|
This is dependent on the password hashing function, however. If the password was stored with a password-specific hashing function, such as bcrypt, these estimates could be severely increased with an appropriate work factor.
See my blog post at https://pthree.org/2016/06/28/lets-talk-password-hashing/ which talks about the cost work factors of: