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Comment by Robin_Message | Hacker News Reader

If I was a customers, I'd be asking if "based on SHA-512" means some kind of iterated algorithm, or if have they lost my password?

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It doesn't matter; you should assume your password is lost.

Follow their advice: "we advise you to change the password for your user name."

It matters a great deal (well, not to me, I don't use the service). Password reuse is common, and the way to fix that is good quality password hashing. If I used OVH, I'd need to change my password everywhere now.

If I used someone competent (i.e. they still have bugs but they use bcrypt), they'd have lost: $2a$10$NkYCXBjWeVP0rJUlfl0VL.d66EvJjbVUA/YEsmBSyTZOnbY0/anxa which is a bcrypt hash of my most secure password.

I'm happy to publish that. The salted SHA-512? Not so much!

Password reuse is a really bad idea, regardless of how the password is stored. Depending on how the server is comprised, your password could be intercepted before it is hashed. Don't reuse passwords for sensitive stuff.

And yet.

Password reuse is still bad, your password doesn't have to be breached through a database dump. You could be accessing a compromised site, or get caught by any number of network attacks from stripping to mixed scripting to dumping a stream that doesn't have forward secrecy. https://www.imperialviolet.org/2012/07/19/hope9talk.html

My point was, if they hash properly, a simple db dump is not a big deal (although obviously considering the password compromised is sensible, and password reuse is a bad idea which is not a proof people don't do it).

I'm signing out of this thread as my point seems to have been lost somewhere. Thanks for the interesting link though.

> I'm happy to publish that

foolhardiness is not bravery ;)

No, the password should now be considered compromised regardless of how it was hashed and regardless of how many other sites you used it on and how annoying it would be to change them all.

$2a$10$NkYCXBjWeVP0rJUlfl0VL.d66EvJjbVUA/YEsmBSyTZOnbY0/anxa == hunter2

"based on" could literally mean "some shit our lead developer cooked up that's like SHA but not really."

I would hope "based on" doesn't mean that but why use the phrasing at all? Either it's SHA-512 or it isn't and if it isn't, confidence is definitely not instilled.

Not everyone is native english speaker. He means the password is salted and SHA-512 hashed...

That jumped out at me as well. People need to understand that even cryptographic hashes cannot be considered irreversible for short inputs, and that you need to use something specifically designed as a password hash to do it properly.

http://throwingfire.com/storing-passwords-securely/#notpassw...

http://codahale.com/how-to-safely-store-a-password/

Maybe SHA-512, salted?

Yep, in the french version of the message they specify that it's salted.

http://travaux.ovh.net/?do=details&id=8998

Salted SHAx passwords are basically the entire reason GPU John The Ripper and oclHashcat exist, although SHA2-512 is significantly slower than SHA2-256, so if you're going to use a terrible SHA-based password hash, SHA2-512 is your best bet.

SHA512 is slower on most (all?) current GPUs, but there is plenty of hardware on which it is faster than SHA256.

Hm. Example?

It'll (theoretically) be faster on any hardware that supports 64 bit operations, as SHA512 ends up doing fewer block operations.

This assumes you're hashing something at least 8 bytes long, and that your hash implementation is smart enough to use the 64 bit capabilities of your platform.

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