Comment Re: There we go again (Score 0) 383
And before the grammar nazis come out, yes I accidentally typed you're instead of your. Let me go commit seppuku now.
And before the grammar nazis come out, yes I accidentally typed you're instead of your. Let me go commit seppuku now.
Hey Desler I really don't get you, you (appear to) know what a salt is yet you don't understand that an attacker would be performing the attack on the hash offline, with their own hardware. Rate limiting their own hardware would be, as you put it, the height of idiocy.
Except what you are talking about was not what I was originally responding to. You basically injected yourself into the conversation and completely changed the context and then started calling me an idiot. I suggest you re-read what I originally responded to:
They can be, but it would be incredibly stupid to use something like that. A dictionary attack would crack that password in seconds.
What I do is have a single, strong password that I have stored only in my brain and all other passwords are hashed on-the-fly from that and the domain or name of whatever I need the password for. I get unique, strong password for everything, but only have to remember a single one.
Do you notice that nowhere in that quoted statement is there anything about the attacker already having the password hash?
You probably shouldn't try to write about things you don't know about or understand.
My irony meter exploded.
1. The industry accepted way to store passwords securely in a database is with a one-way, salted cryptographic hash (using as CPU intensive algorithm as possible).
Duh. Being Captain Obvious again?
2. Many organisations have had database intrusions where these password hashes have been stolen (eg. eBay [threatpost.com], Linkedin [sophos.com], LivingSocial [arstechnica.com] etc.)
Yes, they have.
3. When this happens (i.e. "they have a copy of the password hash") passwords can be cracked offline. Strong passwords are safe (too hard to brute force), but weak passwords can be found using a dictionary attack.
Of course, this is why you lock the accounts until the user resets the password. Poof that attack vector is now gone.
4. Once the password is found offline a hacker can log straight in to the victim's online account with a single password attempt.
Only if you're system admins are dumb enough to not do what I state above.
Only if the passwords haven't been salted properly. Even then, a rainbow tables attack can also be thwarted by the same techniques I mentioned above. Allowing any attacker the ability to do 10s of millions if not a couple of billion (with powerful enough hardware) tries a second to brute force a password is just the height of idiocy. Using constant time password checking, rate limiting, cooldown periods and as a last resort IP bans makes you such an unattractive target that they usually just move on to some other insecure site.
Forgot to close my quote tag so fixing it.
However if a chosen password appears in a password dictionary than you can cut down your brute force search space by so much it goes from taking years (even centuries) to crack a password to taking a few hours (sometimes minutes).
Yes, that's why you stop such attacks by rate limiting and cooldowns and then eventually just ban their IP if they are just obviously an attacker. If they can only have 5 tries every 15-20 minutes the attacker is going to give up unless the user's password just happens to be near the very beginning of the dictionary.
You seem to have no clue what a password hash actually is.
Nope, you're just a poor mind reader.
Yes, that's why you stop such attacks by rate limiting and cooldowns and then eventually just ban their IP if they are just obviously an attacker. If they can only have 5 tries every 15-20 minutes the attacker is going to give up unless the user's password just happens to be near the very beginning of the dictionary.
And to further add, combined with timing attacks and any other potential weaknesses the key space of that 50 character password can be dramatically reduced.
To add above, just because the brute forcing theoretically might take a long time is no reason to allow someone to have unlimited tries. You never know when exactly their brute forcing will stumble upon the password. The user's password could potentially be within the first billion or so tries which means they could potentially brute force it in the first second with powerful enough hardware.
Based on what do you falsely assume that?
Thanks for suggesting everyone configure their system such that I can DOS them!
It's better than allowing someone to brute force account passwords. When combined with IP banning when seen that someone is just trying to attack the system your DOS attack would be short-lived.
Yeah, and I can unlock your phone without being locked out by the authentication program if I know your PIN. Were you going for a Captain Obvious award or did you think a tautological statement was somehow insightful? But if the attacker knows the password hash that is not a dictionary attack. In fact, there would be no need for any attack at all.
To clarify, I should say any brute forcing attacks rather than just dictionary attack. Any authentication program that allows unlimited tries without any rate limiting is totally broken.
Rating limiting = rate limiting.
Only if you're dumb enough to let authentication program be suspceptible to such an attack. Dictionary attacks can be trivially defeated by rating limiting tries and after, say, 5 tries not allowing any more attempts for some cooldown period. No attacker is going to bother if they can only have 5 tries every 15 to 20 minutes.
Maybe it should have been written in Wyvern to be more secure?
To thine own self be true. (If not that, at least make some money.)
