How to steal Bitcoins that are protected by weak passphrases • Hacker News Board

Re: How to steal Bitcoins that are protected by weak passphrases

#51

Post by easy_rider » Sat, Mar 08, 2014, 9:20 PM UTC

easy_rider wrote: post #15

People should really understand the part "phrase" in "passphrase". Can't really have any sympathy for people who are apparently computer savy enough to create a bitcoin wallet and then protect them with "blah"

Ok, get why this is downvoted. It's a bit of a throwaway comment, and the problem is not with the users I guess - although I do feel in this case people should know better. but let me elaborate:

Really the only way people now get educated is by using enforced formats on password fields [1]. That is not are not solid in any way, nor is the proposed 4 random words method (although better). But both are still better than allowing people to use weak passwords when it's involving money.

Every bank these days has 2-factor auth to allow transactions. Sure someone can phish your credentials from whatever, but the transaction authorization itself is only one-time, while with Bitcoin you can transfer money if you've stolen the wallet.dat and can bruteforce the key...

There is no protection (throtteling, locking) on bruteforcing wallets. Usually with banks, or most 2-factor auth implementations, there is.

[1] http://xkcd.com/936/

Re: How to steal Bitcoins that are protected by weak passphrases

#52

Post by lolbrainwallets » Sat, Mar 08, 2014, 9:21 PM UTC

cheesemunger wrote: post #46

thesimpsons1022 wrote: post #35

Earlier quoted context omitted.

I am interested :D

Here you go: http://i.imgur.com/XmOqvvW.jpg I have a few more but they are even more confusing. Red nodes are brainwallets and blue nodes addresses that brainwallets transfer to. You will notice the massive cluster on the left, that is the 'researcher' who is actively probing the network. The rest are standard brainwallet transactions and thefts. The big red dot is a bug :P Hope that was useful

I think the cluster at the end of July/beginning of August of 2013 was me. I am not entirely sure because it was during BlackHat/defcon and I was drunk. Was a few thousand sampled from the rockyou list? Post a pgp key I have a question for you.

Re: How to steal Bitcoins that are protected by weak passphrases

#53

Post by TrainedMonkey » Sat, Mar 08, 2014, 9:23 PM UTC

lvs wrote: post #42

enscr wrote: post #29

Conspiracy theory : Is directory.io phishing ? It is possible that people would try to find their private key on directory.io for fun. You can do that by jumping to the relevant page. Meanwhile, the servers at directory.io would cache the GET requests and blast through the handful of keys on that page. The site is likely generating the pages on the fly. You can type directory.io/ x : 904625697166532776746648320380374…

> The site is likely generating the pages on the fly. The site is definitely generating hashes on the fly. There is not enough known storage in the universe for all possible 32 byte private keys. To be more precise, 1E77 is within a few orders-of-mag of the estimated number of atoms in the universe.

Observable universe.

Re: How to steal Bitcoins that are protected by weak passphrases

#54

Post by easy_rider » Sat, Mar 08, 2014, 9:38 PM UTC

easy_rider wrote: post #51

easy_rider wrote: post #15

People should really understand the part "phrase" in "passphrase". Can't really have any sympathy for people who are apparently computer savy enough to create a bitcoin wallet and then protect them with "blah"

Ok, get why this is downvoted. It's a bit of a throwaway comment, and the problem is not with the users I guess - although I do feel in this case people should know better. but let me elaborate: Really the only way people now get educated is by using enforced formats on password fields [1]. That is not are not solid in any way, nor is the proposed 4 random words method (although better). But both are still better tha…

Maybe the persons who downvote would love to comment on why? Feedback and criticism are helpful..

Re: How to steal Bitcoins that are protected by weak passphrases

#55

Post by lvs » Sat, Mar 08, 2014, 9:41 PM UTC

TrainedMonkey wrote: post #53

lvs wrote: post #42

Earlier quoted context omitted.

> The site is likely generating the pages on the fly. The site is definitely generating hashes on the fly. There is not enough known storage in the universe for all possible 32 byte private keys. To be more precise, 1E77 is within a few orders-of-mag of the estimated number of atoms in the universe.

Observable universe.

You're right; I failed to consider the possibility that this website stores integers in the unobservable universe. My bad.

Re: How to steal Bitcoins that are protected by weak passphrases

#56

Post by kordless » Sat, Mar 08, 2014, 9:50 PM UTC

TrainedMonkey wrote: post #53

lvs wrote: post #42

Earlier quoted context omitted.

> The site is likely generating the pages on the fly. The site is definitely generating hashes on the fly. There is not enough known storage in the universe for all possible 32 byte private keys. To be more precise, 1E77 is within a few orders-of-mag of the estimated number of atoms in the universe.

Observable universe.

I'd l̶i̶k̶e̶ t̶o̶ will drink beers with you someday.

Re: How to steal Bitcoins that are protected by weak passphrases

#57

Post by mpyne » Sat, Mar 08, 2014, 9:53 PM UTC

easy_rider wrote: post #54

easy_rider wrote: post #51

Earlier quoted context omitted.

Ok, get why this is downvoted. It's a bit of a throwaway comment, and the problem is not with the users I guess - although I do feel in this case people should know better. but let me elaborate: Really the only way people now get educated is by using enforced formats on password fields [1]. That is not are not solid in any way, nor is the proposed 4 random words method (although better). But both are still better tha…

Maybe the persons who downvote would love to comment on why? Feedback and criticism are helpful..

I didn't downvote either comment, but complaining about downvotes is typically the very most effective way of ensuring your comment blends into the background here. :P

Re: How to steal Bitcoins that are protected by weak passphrases

#58

Post by 13throwaway » Sat, Mar 08, 2014, 9:55 PM UTC

enscr wrote: post #29

Conspiracy theory : Is directory.io phishing ? It is possible that people would try to find their private key on directory.io for fun. You can do that by jumping to the relevant page. Meanwhile, the servers at directory.io would cache the GET requests and blast through the handful of keys on that page. The site is likely generating the pages on the fly. You can type directory.io/ x : 904625697166532776746648320380374…

Directory.io is not phishing. The chances of someone finding an adress that has ever been used by anyone ever, (aside from people sending coins to the first one for fun) is impossible.

Re: How to steal Bitcoins that are protected by weak passphrases

#59

Post by mpyne » Sat, Mar 08, 2014, 9:57 PM UTC

intelliot wrote: post #20

The human mind can't generate enough entropy to create a secure brainwallet in that way. However, the reverse is permissible: use Bitcoin Armory or Electrum to generate a wallet, and then you should memorize the BIP39 mnemonic: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawi...

Using the passphrase as both the salt and password for the PBKDF2 step strikes me as suspicious, but as I don't do crypto for my day job I'm not sure how bad this is (or isn't).

Re: How to steal Bitcoins that are protected by weak passphrases

#60

Post by sodastream » Sat, Mar 08, 2014, 10:10 PM UTC

Brain wallets should never be used. Even experts fail at picking phrases with enough entropy.

Full stop.

You should be very carefull with your Bitcoin.

I would go with one of the zero trust multisignature wallets because I like 2factor and I don't like the idea of some malware taking the funds away at will when it finds a key in memory.