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Those 500K Bitcoins that caused the flash crash weren't real

mtgox.com

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Re: Those 500K Bitcoins that caused the flash crash weren't real

#151

Post by mcherm »

nowarninglabel wrote: post #90
eli wrote: post #48

Earlier quoted context omitted.

An exchange. That accepts deposits. And holds your money for you. Like a bank.

A bank is a legally defined concept, this exchange is not one.

By that argument, an exchange is a legally defined concept and MTGox isn't one of those either.

MTGox is not a legally regulated bank. They are not a legally regulated exchange. They DO hold accounts on behalf of their customers, performing the function known as "banking". They DO execute trades between their customers, performing the function known as "an exchange".

Re: Those 500K Bitcoins that caused the flash crash weren't real

#152

Post by hackinthebochs »

danssig wrote: post #129
dkersten wrote: post #67

Earlier quoted context omitted.

I wouldn't store my money on facebook either.

I wouldn't either but that's because I can imagine Facebook just straight-up stealing it. Nothing about security.

Totally off-topic, but I find this attitude curious. What makes you think facebook would do something of that sort? What possible evidence do you have for the potential of this sort of outright criminal behavior?

It seems to me your loathing of facebook is completely irrational. Unfortunately its this irrationality that drives most discussions regarding facebook in tech circles.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#153

Post by daeken »

bnr wrote: post #136
daeken wrote: post #22

Earlier quoted context omitted.

By using floating point values for a user's balances (per-currency) in the DB, they effectively did make themselves a fractional reserve bank, even if the spread was likely small. Most every transaction would've added a tiny bit of an error value -- given enough time, this would've added up pretty considerably.

IIRC that was Bitcoin7, another exchange, called out for using floats to store balances.

Bitcoin7 was called out for floats, but they actually weren't. MtGox was, but isn't anymore. It was reported in full disclosure, then confirmed on IRC later, although I don't have logs handy.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#154

Post by hobolobo »

white_devil wrote: post #117
Xk wrote: post #34

Earlier quoted context omitted.

> don't disagree with most of what you said, but...you sure about this part? Yes. I am sure. I have far, far, far less than 0.000001% of the total money in the bank. If they could not produce this much money when I wanted it, there would be other serious problems. > Or if you want a more practical example, keep watching Greece If I was in Greece, I would not have my money in one of their banks.

> Yes. I am sure. I have far, far, far less than 0.000001% of the total money in the bank. If they could not produce this much money when I wanted it, there would be other serious problems. Last year, a branch office of a large bank in Finland was barely able to produce 10 000 euros in cash when I wanted to withdraw it. The clerk just didn't realize he shouldn't mention it. Don't be so sure.

Is that a case of the bank not having the money or just that branch not having the cash on hand?

Re: Those 500K Bitcoins that caused the flash crash weren't real

#155

Post by uxp »

gojomo wrote: post #58
uxp wrote: post #43

Earlier quoted context omitted.

Why reinvent the wheel using engineering techniques you only have cursory knowledge of from reading an encyclopedia? There is a standard method of securing online accounts, using known methods that are currently known to be perfectly safe in every application from financial institutions to the latest social networking site. Triple-salting passwords is not that method. http://codahale.com/how-to-safely-store-a-passwor…

I wasn't advocating this method or defending Mt. Gox. (Their touting of SHA-512 and use of the unclear term 'triple salted' raises red flags.) I was providing an example of what could be meant by 'triple salting' that didn't necessarily involve 'three servers'. We could contrive scenarios where bcrypt with this multisource-salt would be a win over bcrypt with a single same-database salt. Intellectually exploring the…

No, we haven't worked together. My "cursory knowledge" comment was more directed at the people running MTGox, not you. Sorry if I phrased it in such a way to imply so.

I agree, there could be an implementation where applying multiple salts might have a benefit, but SHA-512 is not that implementation. I was not slavishly repeating 'standard methods', but pointing out that they are or were widely wrong in whatever they were doing to begin with. An MD5 is hilariously weak for password hashing, and salting an MD5 only makes an extremely weak password hashing scheme moderately weak. It honestly sounds like they took the first hashing implementation with the largest number tacked on the back of it that came to mind and called it good. This is not the right thing to do, and anyone that 1) cares about the security of their online web app's users information, and 2) has spent more than 2 minutes reading about the correct ways to secure an online web app, should be able to figure this out.

Point being, the fact that they originally only had MD5, and then "upgraded" to a salted MD5, and now are going to a triple-salted (whatever that means) SHA-512, is a BIG clue that they really don't know what they are doing, and a complex homebrew triple salt implementation that passes a password to 3 different places to be salted is bound to be broken. Unless they have hired a well known experienced cryptographer, I wouldn't trust MTGox with a dime of my internet money.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#156

Post by anonymous246 »

Locke1689 wrote: post #71
drivebyacct2 wrote: post #57

Earlier quoted context omitted.

I was more referring to the fact that we fail to produce proof of the limited amount of gold that we claim to have and every attempt to audit it is rebuked magically. In terms of the question, how would it be handled from an FDIC perspective if it came to a worst case scenario... it'd be a shit-show.

I was more referring to the fact that we fail to produce proof of the limited amount of gold that we claim to have and every attempt to audit it is rebuked magically. I think you're just rambling. Our currency isn't gold backed -- who cares how much the US govt. has in gold repositories and why does it need to be checked?

I think he's talking about the repeated rebuffs to the calls for audits of the supposed gold at Fort Knox by people such as Ron Paul (http://www.foxnews.com/politics/2010/08/31/rep-paul-calls-fo...)

The "conspiracy" theory goes that this gold has either been loaned (that's why Ron Paul phrased his question to also check if they're "obligated") or sold to drive down gold price thereby making dollars are more attractive investment than gold. Hence the call for an audit. The "conspiracy" theory further suggests that all the world's central banks are doing this.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#157

Post by yaakov34 »

by wrote: post #126
yaakov34 wrote: post #104

Earlier quoted context omitted.

No, it doesn't. Once the salt is large enough that you don't have several passwords hashed with the same salt value, there is absolutely no further advantage. Frankly, 64 bits of salt seems like enough for anything. Triple-salting sounds like a technique made up by an amateur who doesn't understand what salting is supposed to do.

"The length of the randomly generated salt shall be at least 128 bits." nist-sp800-132.pdf http://csrc.nist.gov/publications/PubsSPs.html Not quite the same application, but it would seem best to take a conservative approach and make your salts 128 bits because the storage required is so small - you are only storing one per username.

Right, but this doesn't make the search space 2^64 times larger, or anything of the sort. Once you've assigned a unique salt to every password, you're not getting any further benefits from salting. This is what the Mt. Gox owner doesn't seem to get, with his "triple-salting".

The NIST application involves generating keys from passwords, which you might do a gigantic number of times for every password to get unique sessions and so on. They're not talking about password storage. And even then, 128 bits seems like a huge overkill, which was included just because it's cheap, so why not. I don't mind 128-bit salts, but let's not promote that as some "ultra-secure" feature, which it isn't.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#158

Post by nowarninglabel »

RickHull wrote: post #125
nowarninglabel wrote: post #97

Earlier quoted context omitted.

Not really no, a bank is a legally defined concept in pretty much every country in the world. Suggested reading: http://www1.law.nyu.edu/centralbankscenter/texts/order.html

That page links to the national laws defining central banks. No one is claiming Mt Gox is a central bank.

It's a further resource out to the central bank information in various country which further goes towards information on legal definitions of a bank in each country (at least many of the links provide such information). If you have a better site for international banking law definitions separated by country, it'd be awesome to suggest it.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#159

Post by gojomo »

daeken wrote: post #130
gojomo wrote: post #28

Earlier quoted context omitted.

Not necessarily. Let's say the salt is a combination of a per-user salt in the database, a per-user salt from a file on disk, and a per-system salt that's entered at the console at startup and held in memory. A DB compromise doesn't reveal the other 2 salts. A full filesystem image doesn't reveal the third salt. Even an interactive root compromise would need to know to take an image of the running system's memory to…

There are plenty of ways that you could use 3 different salts without it having to pass through 3 servers, but I was specifically responding to the OP, where he spoke of 3 salts in 3 different servers.

Yes, I should have addressed my example more specifically to the seanalltogether parent comment's assumptions.

Re: Those 500K Bitcoins that caused the flash crash weren't real

#160

Post by romey »

I'm wondering why they don't offer users the option of using two-factor security, like Google recently made available to Gmail/Google App users. Being able to tie my gmail login to a secure passcode generated on my phone makes me feel a good deal safe, and I don't even have any really important information in my Gmail inbox.
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