Bitcoin Forum

Bitcoin => Project Development => Topic started by: fpgaminer on May 04, 2013, 12:58:11 AM



Title: How Much Is Your Password Worth? Find out!
Post by: fpgaminer on May 04, 2013, 12:58:11 AM
How Secure is Your Password?

One of the side effects of the Bitcoin network, is establishing a lower-bound on the cost of password cracking.  Suppose someone has a mining farm; they can either use their equipment to mine or crack passwords.  If the reward from cracking a password is less than they would earn mining, they will likely mine instead.  Hence, the price of a bitcoin, and the mining difficulty, can be used to figure out just how much it costs to crack your passwords!

http://bitcoin-password-cost.appspot.com/ (http://bitcoin-password-cost.appspot.com/)

The "Time to Crack" result assumes the entire Bitcoin network is attacking your password.  The "Cost to Crack" is agnostic to the attacker's hashing rate, though.


Example:
10 Character Password
Alphanumeric, Upper/Lowercase, Special Characters
PBKDF2_HMAC_SHA256 - 100,000 iterations

Time to Crack (50%): 1.06 Thousand Years
Cost to Crack (50%): 128.71 Billion USD


Notes
This is likely to be an underestimate.  In other words, it will probably cost a real attacker much more, since they also need to pay power costs, capital investment, and password cracking algorithms will be far less efficient compared to the current mining algorithms.  They are also likely to have only a fraction of the computing power relative to the Bitcoin network.  The effective cost to crack your password would remain the same for them, but the time would be much, much larger.  Anything much over a few years time seems too long for anyone to even attempt.

On the other hand, computing power tends to double every two years.