Key Question: The monitoring service is relatively cheap, but what is the average cost of the hardware that you need to make it run correctly? (theworldsbestrealestateagent.com)
While developing Tarsnap, Percival devised an algorithm called scrypt, which he estimates can make the «cost of a hardware brute - force attack» against a hashed password as much as 4,000 times greater than bcrypt. (scientificamerican.com)
And the added cost of the hardware (which is not needed to read paper books) is only paid by the reader. (goodereader.com)