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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

I agree that there is no excuse not to use bcrypt.

You can do basically attempt all 8 character passwords in a few minutes per user on modern hardware (the salt adds 0 computation complexity, but as you say, it forces you to actually have to do the calculation instead of doing a lookup).

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

Also, the whole point is that key derivation is slow. Of course the "secret from which keys are derived" is available (it is necessarily so; it's stored, along with the cost factor, as part of bcrypt's output, for example). But the fact that you have to through 2^N iterations, where N is usually >= 10, throws a meaningful speedbump in front of high-speed cracking. Now instead of brute forcing any given 7-character alphanumeric case-sensitive passwords in ~half an hour, it'll take you > 20 days on average.

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

The key derivation functions can be literally several orders of magnitude harder to brute force. And their difficulty can be chosen with simple parameters, with sane defaults. There is really no comparison between a singly salted hashed password and bcrypt/scrypt.

Check out table 1 in this paper to get a sense: https://www.tarsnap.com/scrypt/scrypt.pdf

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

Assuming the cracker has access to the salt and a GPU, the only thing keeping users safe now is the entropy inherent in the passwords they chose.

It doesn't have to be like that. Instead of plugging in Good Salted Hashed Password Library, you can plug in Bcrypt Library or Scrypt Library *and protect even the users who chose bad passwords*.

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

Can you explain this a bit more?

If the hackers didn't get the salt, and only have the salted hashes, and let's say the salt is, say, a 20 character random phrase using numbers, letters and symbols, what is the weak spot?

I'm sure many /. users are implementing systems like this using salted hashes, so if there's an inherent weakness (other than the salt becoming exposed) I'm sure it would be useful if there was a straightforward explanation.

The size of the salt is relevant only insofar as you want to be sure that each user has their own unique salt. The salt is stored in plaintext (or, I suppose, it could be encrypted, but then the decryption key must then be stored in an accessible place). The point is that the crackers must be assumed to have recovered the salts.

So now those salts protect you against pre-computed hashes. The cracker has to attempt each password individually. But most people use one of the few thousand most common passwords. And inexpensive modern hardware lets you attempt billions of SHA hashes per second. So... Salted and hashed does very little for you at this point.

Instead of salting and hashing, use a key derivation function (e.g., bcrypt, scrypt).

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Re:Hashed and salted is obsolete (80 comments)

And yet, with no extra effort on Living Social's part -- simply by choosing a bcrypt library instead of a custom hash/salt scheme -- even a user with a weak password would be protected.

So, sure, I might agree with you, but that doesn't absolve Living Social.

about a year ago
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LivingSocial Hacked: 50 Million Users Exposed

SUB7IME Hashed and salted is obsolete (80 comments)

Why is it "fortunate" that the passwords were hashed and salted? Unless they've used key derivation functions (e.g., bcrypt, scrypt) and are actually under-selling their sophistication, this seems Very Bad for their customers.

about a year ago
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Central Dogma of Genetics May Not Be So Central

SUB7IME Re:NEWS FLASH (196 comments)

... RNA misspellings originally discovered in the white blood cells were also in the skin cells. And the misspellings aren’t just rare, random mistakes. “When DNA and RNA differ from each other it happens in nearly every RNA” copy, Li says.

This supports what canajin56 was saying.

about 4 years ago
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O2 Scraps Unlimited Data Usage For Smartphones

SUB7IME Re:Why do I not trust their numbers? (272 comments)

Well, yeah, my tax dollars subsidized their infrastructure, so I would like to regulate their pricing.

more than 4 years ago
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In Brazil, Google Fined For Content of Anonymous Posting

SUB7IME Re:Probable end result (484 comments)

Even if Google never pays another fine for Orkut-related activities, is Orkut in Brazil profitable per se?

more than 4 years ago
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Flaw In Emergency Response System May Have Killed Hundreds

SUB7IME Re:More like a flaw in statistics (437 comments)

Yes, that's the right thing to do. As I said the first time, "Ambulances in the US will take you to the nearest hospital with appropriate facilities for your condition." Since the hospital that was a bit further was a facility more appropriate for your grandmother's condition, it was right to take her there.

more than 4 years ago
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Israel's Supreme Court Says Yes To Internet Anonymity

SUB7IME Re:Torturous? (198 comments)

Getting warmer. Tortious.

Unless they actually meant torturous - but most blogs aren't THAT bad.

more than 4 years ago
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Flaw In Emergency Response System May Have Killed Hundreds

SUB7IME Re:More like a flaw in statistics (437 comments)

Just replying so that people know not to take your post literally. Ambulances in the US will take you to the nearest hospital with appropriate facilities for your condition.

more than 4 years ago
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Hotmailers Hawking Hoax Hunan Half-Offs

SUB7IME Re:Sorry, no. (135 comments)

Did you read the rest of my post (the part that you didn't quote) where I addressed the actions that they should take, instead of just turning off autoreply?

Your tone seems to be that of disagreement, but your words recapitulate what I already said.

more than 4 years ago
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Hotmailers Hawking Hoax Hunan Half-Offs

SUB7IME Re:tl, dr (135 comments)

Regardless of the information density of his post, I disagree with his assertion that Hotmail should flip the 'autoreply' bit on these accounts. I do not think Hotmail wants to get involved in guessing whether or not someone intended to set any particular auto-reply message: "Surely, Mr. Jones, you didn't intend to drop an F-bomb in your auto-reply."

More to the point, these are hacked accounts. If you were going to take any action, *disabling* (even temporarily) the accounts and flagging them for forensic follow-up would strike me as more appropriate.

more than 4 years ago
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Slovak Police Planted Explosives On Air Travelers

SUB7IME Re:Seriously? (926 comments)

Your point is supported by the fact that the Christmas terrorist was the son of a banker, and well-educated. This is not someone who spent a life in poverty.

more than 4 years ago
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The Environmental Impact of PHP Compared To C++ On Facebook

SUB7IME Re:Umm... no. (752 comments)

This is the correct response. Facebook use (and actively develop) APC, an opcode cache. In other words, they cache the compiled binaries created by PHP. So, the environmental impact of running PHP as opposed to something compiled is virtually 0, because nearly all calls are made to pre-compiled PHP opcode.

more than 4 years ago

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