[Keyblctt]

oh, it's MD5. Wouldn't SHA1 or SHA512 take a lot longer? And unless you have access to the actual hash of the password along with the salt, you wouldn't be able to solve it this fast because it takes time to make each guess. If you have physical access to a system which is what is required to get the hash and salt, then you can already consider your data to be toast.

[goldcigarettes]

SHA1 isn't much better. SHA256 or ideally 512 would be best.

And yeah, basically this is only useful if you have access to the physical system, or you have the password hash otherwise (like hacking in to the database, a la Sony).

[pokerbonuscod]

SHA1 isn't much better. SHA256 or ideally 512 would be best.

I believe HC was talking about the runtime of the hash - IIRC MD5 is much faster (to compute) than any of those.

[Olympicdreams]

This only affects passwords to turn on a computer, right? Not like Internet passwords?

All passwords.

[soyclocky]

They can bypass the protection against multiple failed entries?

No. This is more useful if, say, you hack in to a server and steal 100M user accounts with encrypted passwords. You can then decrypt the passwords and get them all.

Or if you have physical access to a computer, you could extract the encrypted password from the disk then crack it.

[AnthonyKing]

It might be possible to write a program to strengthen systems with inadequate password protections. Let's say my online bank password has a maximum of 15 characters with certain restrictions (e.g. requires one uppercase, one lowercase, and one number); then all I need is a program to generate salted SHA512 hashes. When I need to login I enter my arbitrarily long passphrase into the password generator, and it outputs 15 String64 characters and truncates the rest of the hash. The program would iterate through salts until it generated a hash that met with the password requirements, which in most cases shouldn't take too long (all password restrictions I've seen are of the "at least one of" variety, with only lowercase, uppercase, number, and special characters being in the "at least one of" category; the only time there would be a problem is if the password is obscenely short, e.g. at least one uppercase, one lowercase, one number, and one special character in a password with at most 6 characters, but in that case your password is going to suck no matter what you do so you might as well make it human memorable.)

[bushomeworkk]

Be quicker than remembering my password.

[deermealec]

There's also the security question process. All of my banking sites now require I answer one of 5 or more security questions I set up before gaining access to the system. Stuff like "What was your first job?"

I truly hate this practice. It's like the password recovery options on most sites that only give you a handful of generic questions that could be easily guessed based on publicly known data. I stopped using a bank not long ago because they did this and the hardest question they could come up with was "what was your high school mascot?".

[Lydiaswingert]

If your drive isn't encrypted, the password isn't worth anything if your physical access is compromised. TPM's pretty tough to crack if you do have encryption, though. But at the end of the day, you may as well assume a stolen drive = stolen data.

[happyman]

I use a portable browser located on an encrypted partition, so if anybody steals my laptop they won't have access to my cookies or saved passwords.

[himecthekWiff]

I remember some researchers fooling fingerprint scanners with silly putty. Let me see if I can find the article.

[GotActichwicy]

Vein maps

[Hbkj89D2]

Iris scanners are much more reliable, because the iris pattern doesn't change during a person's lifetime and is unique. The problem is that an iris scanner does not include a liveness test, because an iris from a severed eye looks the same as an iris from a living eye. However, it's possible to combine the iris test with a retinal scan; retinas are not as accurate as irises because the capillary pattern can change during somebody's lifetime (capillaries break and new capillaries are formed), but a retinal scan can include a liveness test - check to see if blood is pumping through the capillaries.

[LottiFurmann]

That's relatively easy to protect against - if the connection to the sensor is ever cut then the alarm goes off.

[Mangoman]

Likewise a cryptoprocessor is surrounded by a wire mesh - if a wire is cut then the processor wipes its memory. The danger is that SRAM (which is what's typically used to store the keys) retains its charge for quite awhile if subjected to a very low temperature, so the danger is that somebody is going to dunk the cryptoprocessor in liquid nitrogen, destroy its battery, extract the memory, and read off the data before the SRAM loses its charge; without a battery the cryptoprocessor can't detect that its mesh is being cut and also doesn't have the power to wipe its memory. The solution is to include an environmental sensor that will wipe the memory if the temperature gets too low, but that makes it difficult to transport cryptoprocessors and also means they're not suitable to extreme environments. But, such is life.

[Keyblctt]

I truly hate this practice. It's like the password recovery options on most sites that only give you a handful of generic questions that could be easily guessed based on publicly known data. I stopped using a bank not long ago because they did this and the hardest question they could come up with was "what was your high school mascot?".

The questions are not there to protect against people who personally know you from getting into tour account. It's to prevent hackers who buy your password from some hacked site from gaining access to your account. It's very effective for that.

[oplapofffe]

It's a lot harder to prevent a determined attacker from getting into one specific person's account than to prevent someone from trying to break into whichever weakly protected account he can find.

[Uttephabeta]

Also, if it's not a laptop then you have very little excuse for compromised physical access.

[OccumCymn]

There'd need to be a way to replace the SRAM after a power failure, either from the battery going bad or from somebody trying to break into your computer. The question is whether the computer manufacturer has the keys, or whether the user does - the former presents another point of failure, but the latter raises the question of where the user is supposed to store the backup SRAM key if not on their laptop (which is inaccessible if they're trying to reprogram the SRAM). The easiest solution would be for the SRAM to contain a user-defined key, which can be generated by SHAing a passphrase; that way if the SRAM loses power the user can re-generate the key. The interface to the SRAM doesn't even need a great deal of protection - if an attacker wipes the SRAM and then attempts to enter a new key then they'll still have a bricked hard drive unless they've entered the correct key.

[Aminkaoo]

The questions are not there to protect against people who personally know you from getting into tour account. It's to prevent hackers who buy your password from some hacked site from gaining access to your account. It's very effective for that.

I know that's the theory, I just think that it's going to be/already is foolish when you can combine the email address that came with that password with a database scraped from Facebook and answer most of the trivial questions they ask.