Note that 44 bits of entropy is still nothing if you want protection from off-line attacks on password hashes. A couple of GPUs together can calculate a billion hashes per second, which eats through 2^44 possible passwords in only a few hours.
This was recently demonstrated when the mtgox password database was compromised.
edit: but this shouldn't be a problem if the password is properly hashed with bcrypt or some other scheme with a work factor.
But this approach scales at a much faster rate. Simply adding a fifth word throws even a billion-per-second attack out into hundreds-of-years territory.
This was recently demonstrated when the mtgox password database was compromised.
edit: but this shouldn't be a problem if the password is properly hashed with bcrypt or some other scheme with a work factor.