Comment by bhousel | Hacker News Reader

Comment by bhousel | Hacker News Reader

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You kind of ignored my point about verifying the person's identity while you have them on the phone.

LAST EDIT: Fine. shibboleths, passwords, pins, safeword cards, emails, texts, callerid, voice, and face to face conversations are all great tools to use when trying to secure some asset. All I'm saying is Go out of band when you want to verify a person's identity. If you are emailing, call. If you are on the phone, and you don't trust them, call them back at their home. Or text them a code and ask them for the code. Or meet in a trusted place and take a DNA sample. Whatever is appropriate for the thing you are securing.

Sure, any of these methods can be compromised through social engineering, blackmail, theft, or violence. That's not the point.

If you care about a password, don't send it through the same channel that you use to verify the person that you are sending the password to. Shibboleths and ROT13ing won't solve the problem of knowing who you are talking to.

How would you identify the person on the phone? Their voice clearly isn't enough. Caller ID can be spoofed. With another password? What happens when they forget that as well? I guess you could require a face to face meeting to reset that password. But by having two alternative passwords, you have increased the attack surface. The user is much more likely to write the second "emergency" password down I expect.

Also, what happens when your helpdesk's VoIP system gets hacked in the same way that the email system got hacked in this case?

Only document the full procedure on paper, and forbid people from mentioning the full procedure except in person. If an admin gets an email asking for a password, they should reply with a fake password, and then await a call to give a real password. Or vice versa. If the person contacting them tries repeatedly, they should feign incompetence and / or laziness, escalating if it gets out of hand (even if escalating means passing to another equal-rank admin.)

This is the right idea. A feedback loop is critical to hacking. If you take away the feedback loop it becomes nearly impossible.

Or just PGP encrypt any emails with root passwords or other details about your system.

Just make sure you decide before the emergency who needs to be trusted with that information, and be smart about how you exchange keys with everyone involved.

>If you are on the phone, and you don't trust them, call them back at their home.

Didn't think of that. Great idea.

We used to do this when managing unreachable firewalls. Dial out to the modem attached to the firewall console and type in that modem's password. The remote modem drops our call, then dials us back with a console login prompt. So even if you had the password, you had to at least be dialing in from our phone line.

old school BBS callback verification!

Reminds me of these tricks: http://www.skepticfiles.org/cowtext/bbs/cbv.htm

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