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Why aren't we using public-key cryptography instead of passwords on the net?

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Deozaan:
I read a good essay/rant on passwords today, which was written/posted yesterday. Here's an excerpt:

When i do my hacker thing and connect to a server from a terminal/console/black box with letters in it, it uses public-key cryptography to prove who i am. I have a private key and a public key. The public key can be used to lock boxes in such a way that only my private key can unlock them again. I give out my public key; the server picks some big random number and encrypts it; if i can tell the server what random number it picked, then it knows i have the private key and must be who i say i am.

(Okay, that's still a bit oversimplified. The actual mechanism for how this usually works is pretty cool, if you want to read about it. It has a pretty picture using paint mixing.)

While my key is still protected by a password, the experience is radically different in a few critical ways.


* It's called a passphrase, not a password. And, indeed, my passphrase(s) tend to be phrases, 50+ characters long, decorated with punctuation in some way that makes sense to me. They're very easy to remember, yet i can't imagine how you'd even approach trying to crack them.
* I type the passphrase in once, when i boot up my machine. The private key is unlocked for the rest of the session, and it's used automatically when i connect to any server that has the corresponding public key. Logins are instant and seamless; i log in and out of stuff all day long.
* The passphrase stays on my machine. It's not sent to the server to be double-checked, like virtually all passwords on the Web are. Something like Firesheep simply cannot work; you can't sniff my passphrase out of the air if it's not there to begin with.
* Even if i connect to server A, and then hop from there to server B, i can defer all the key-checking back to my desktop. Server A doesn't need to have my private key on it to connect somewhere else in my name.
* You know those SSL certificate warnings? You know how you always ignore them? Yeah, you shouldn't do that. They're the only warning you get that someone might have hijacked the connection to your bank or whatever. It's a shame that browsers have trained most of us to ignore the warnings, because they're the only thing making SSL useful.
* Anyway, in the case of SSH: the server has its own public key, which it broadcasts to me as part of the login process. The first time i connect to a server, the public key is remembered on my machine. If i ever try to connect again, and the public key is different, the connection stops immediately. It's the same idea as the certificate warnings, except that public keys are supposed to last forever and you don't need to bleed cash to get one, so a changed key is actually a legitimate cause for concern. (Most SSL warnings are about a certificate that the website owner created himself, because getting a signed one is considerably pricey.)
* And best of all, i can use the same set of keys for any number of servers. Or i can use a separate key for every server. It's entirely up to me. It doesn't matter what my username is on each server. It doesn't matter whether the servers are related in any way. It doesn't even have to be my account; any account can have any number of public keys linked to it, so sharing an account is just a matter of giving it several people's keys.-http://me.veekun.com/blog/2011/12/04/fuck-passwords/
--- End quote ---

I think it's a great read, and it even has a section on the stupidity of bank's websites almost requiring you to have an insecure password. Read the rest of it here. But be warned, it does contain some strong language.

I don't know much about encryption, but the essay seems to make some valid points and it makes me wonder why we use passwords instead of having a single private key to handle all that crap for us.

Mozilla is working on a solution called BrowserID, as discussed here, but as pointed out in the initial post, it is tied to your e-mail account, which isn't necessarily desirable.

So could someone--who presumably has more knowledge than me on this subject--tell me why we are using passwords for every single website we visit when we could just be using public-key cryptography to handle the details for us?

Ehtyar:
Up until recently, browser compatibility. Same reason we're still using dedicated IPs for SSL instead of server name indication. However, I'd agree that there is no longer an excuse for either of these not being implemented.

Ehtyar.

Renegade:
Oh god, I love this guy!

Quote - NSFWConclusion: everything is fucked and i hate computers.


Amen to that! ;D

The guy hits so many things bang on.

For banks... Some of them should be charged with criminal negligence for their crappy security. e.g. A quote from him:

ING Direct: 6–10 digits

--- End quote ---

It gets worse... The Commonwealth Bank of Australia requires 6 digits and exactly 6 digits... Ahem... Perhaps they should be charge with criminal idiocy...

rgdot:
What do you expect from a culture that requires signatures to pay but a copy of the signature is on the back (credit cards)? Then they put in a chip and require four digits...

4wd:
It gets worse... The Commonwealth Bank of Australia requires 6 digits and exactly 6 digits...-Renegade (December 05, 2011, 10:16 PM)
--- End quote ---

WRT personal banking, it must be a different CBA you're talking about, the one I've used since they took over the State Bank of Victoria, (21 years ago), and that I've used NetBank with since it came out, (1997), have always allowed more than 6 digits....I know, my password has always been longer than 6 digits, (my wife uses an even longer password).
When I started using Netbank, a mix of alphanumeric characters wasn't mandatory but it was 2 years ago when my wife joined up, (it wouldn't let her create one that didn't have at least one digit and one character).

Your new password:

    must be between 8 and 16 characters long
    must contain both letters and numbers
    must be different to your previous 5 passwords
    should not contain a recognisable part of your name or your date of birth
    must not contain your NetBank client number
    can contain most characters except <>^`{}~=

--- End quote ---

Then there's your 8 digit client number to remember on top of that.

CBA Phonebank is the same, can be alphanumeric characters and longer than 6 characters.

And, if you're talking about ATM pins, then anything between 4 and 8 12 digits is fine, (mine is 8) - and that's been available for about 5 years.

Also, they'll send you a one off PIN via SMS when you try to pay a third party via NetBank for the first time or use a website that requires verification...providing you have that function turned on.

So, what particular service of CBA that requires exactly 6 digits are you talking about?

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