Live data from Hacker News

Dropbox: Security update & new features

blog.dropbox.com

11–20 of 69 posts

Re: Dropbox: Security update & new features

#11
post #8

Earlier quoted context omitted.

If the number of salts used in the system is equal to the number of users, this could be expensive.

They will just check your password against a list of 'bad' passwords when you log in. No need to brute force the stored hash.

Obviously that would work, but not if you're using Challenge-response authentication. In general, I don't think people bother with now that when using https.

Re: Dropbox: Security update & new features

#12
post #4

> In some cases, we may require you to change your password. (For example, if it’s commonly used or hasn’t been changed in a long time) This is ambiguous...by "commonly used" do they mean 1) I'm logging in with my password frequently or 2) my password itself is a commonly used password? I'm assuming (and praying!) they mean the former since the latter would mean they're storing my password in plaintext. UPDATE: Dropb…

It's quite obvious from context that it's the latter. However, there is zero implication that they are storing passwords in plaintext. There are several ways to implement such a feature.

First, the password could be checked on login when it is sent in plaintext but not stored. Second, they could run an offline dictionary attack against the hashed password database.

Re: Dropbox: Security update & new features

#13
post #10
post #4

> In some cases, we may require you to change your password. (For example, if it’s commonly used or hasn’t been changed in a long time) This is ambiguous...by "commonly used" do they mean 1) I'm logging in with my password frequently or 2) my password itself is a commonly used password? I'm assuming (and praying!) they mean the former since the latter would mean they're storing my password in plaintext. UPDATE: Dropb…

Dropboxer here. We do not store passwords in plaintext, or unsalted. End sentence. :)

How do you store them?

Re: Dropbox: Security update & new features

#14
post #8

Earlier quoted context omitted.

If the number of salts used in the system is equal to the number of users, this could be expensive.

They will just check your password against a list of 'bad' passwords when you log in. No need to brute force the stored hash.

A little bit of googling makes it seem like auth tokens are not sent it plaintext over HTTPS but are authenticated using challenge response – http://forums.dropbox.com/topic.php?id=47952 The WWW site may differ.

Re: Dropbox: Security update & new features

#15
post #9

I'm curious who all received this email? Was it sent to the entire user base? If not, what selection criteria did they use? Everyone I've talked to seems to have received the "reset your password" email. I'm quite curious because I'm certain (up until now) that the password I used for Dropbox was both (a) not commonly used and (b) had been changed recently and (c) not leaked anywhere else (to the best of my knowledge…

I also received the reset email and my password for dropbox was a random string generated by lastpass so I'm fairly confident that it wasn't leaked elsewhere. I wouldn't be alarmed if you got the email.

Re: Dropbox: Security update & new features

#16
post #9

I'm curious who all received this email? Was it sent to the entire user base? If not, what selection criteria did they use? Everyone I've talked to seems to have received the "reset your password" email. I'm quite curious because I'm certain (up until now) that the password I used for Dropbox was both (a) not commonly used and (b) had been changed recently and (c) not leaked anywhere else (to the best of my knowledge…

FWIW, I use Dropbox with multiple accounts and did not receive a "reset your password" email.

Re: Dropbox: Security update & new features

#20
post #19
post #18

The email they sent was unfortunate. It's from no-reply@dropboxmail.com. I presumed it was a phishing attempt.

Likewise. It's the kind of email I always delete.

Agreed. Excessively unfortunate that they didn't send it from @dropbox.com, as I'd never heard of dropboxmail.com.
Post reply on HN