_ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote 8 down vote favorite 1 When you want to anonymize a few hundred BTC, what would be the best (safest) way?I can think of these alternatives: Deposit to and withdraw from exchange (like Kraken, Bitstamp, etc)Pros: reasonably safe (especially when using a solid, trusted exchange).Cons: not really anonymous, major exchanges must subject to KYC laws and have strict identification rules.Mixing service (like bitmixer.io)Pros: very anonymous.Cons: can't really estimate the risk, you have to trust some anonymous 3rd party who can decide to disappear with your coins.Also, it can be expensive (depends on circumstances and requirements, but I'd consider 3 BTC fee to mix 300 BTC kind of expensive).Coin JoinPros: pretty much risk-free (don't have to trust anyone).Cons: is there a steady, easy, accessible way to setup large coin join transactions?

The shared send feature of blockchain.info/wallet?Dark Wallet / Stealth AddressesPros: as far as I understand, this offers high anonimity without the need no trust anyone, although I'm not 100% sure of how this works technically.Cons: To my knowledge it's still in development, unstable, not suitable for usage with large sums of money?ethereum south koreaWhat your take on this?valor bitcoin hojewallet exchanges privacy mixing stealth-address up vote 4 down vote I would say connect to tor, create a blockchain.info account, send you bitcoin there, then send the bitcoin to https://shapeshift.io to another currency which you have a wallet setup, then back to a second blockchain account, then to wherever you want.bitcoin miner apk download

This is pretty much 100% untraceable, as it goes via anonymous wallet - anonymouswallet - converted to another blockchain, sent to anonymous wallet, then converted back to bitcoin through another anonymous wallet!bitcoin hourly chartYou can't track that transaction on the blockchain.bitcoin ceskyEnjoy :) up vote down vote You could try this site: /tiki-index.php?page=SBC It looks like a good option.tips bisnis bitcoinThey're geared toward privacy.bitcoin-qt optionsSimple mixing of coins is free.current bitcoin price audThey're also based in Panama, which will make it more difficult for anyone from elsewhere to access their records.litecoin open source code

up vote down vote The source of shared send in blockchain.info is open source./blockchain/Sharedcoin The limit which blockchain.info offers for shared send is 50BTC.You can check the code and modify the max limit but to mix the coins you should have enough transactions.check lines 62 and 63 in below code: /blockchain/Sharedcoin/blob/master/website/src/piuk/website/SharedCoin.java protected by Community Thank you for your interest in this question.Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).Would you like to answer one of these unanswered questions instead?Browse other questions tagged wallet exchanges privacy mixing stealth-address or ask your own question.Last modification: 8 march 2014.Note This article is also available in French here.Every Bitcoin address is based on a secret key, from which the public key (associated to a Bitcoin address) is calculated.

Once you have the private key for an address, you have the control of that address and can use it to transfer funds.This secret key is a 32-bytes unsigned integer.You can generate a lot of secret keys, calculate the public keys associated to them and see if they contain bitcoins.If it’s the case, you can transfer the money to an address you control, because you have the secret key.Such an attack is completely infeasible, because the private key space is really, really huge.There are secret keys available (1077).Oh, and they are all listed on directory.io !Of course, this website is kind of a joke, and all is calculated on the fly when you request a specific page.It also shows the danger of entering your secret key on an unknown website, for example to see if it was compromised... However, we can bruteforce only a tiny fraction of this space, concentrating on secret keys with some distinctive features.This is what I will explain.Private keys are numbers...So, why not try really tiny numbers ?

I have made a script that tries every secret key, counting from 1.After some seconds, I found dozens of already used addresses, with private key smaller than 100 000 !In particular, the 1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm address (corresponding to the private key 1) was already used quite a lot, as 4 bitcoins already flowed through it.Brainwallet Brainwallet is a website that allow people to create private keys from a passphrase.It calculates the private key from the sha256 of the passphrase.By using a password dictionary, we can search for private keys corresponding to classic password that were already used.A search allowed me to find nearly 10 000 addresses that have contained Bitcoins at some point in time !I was never able to find any address containing money, and nearly every time they had contained only really small amounts of money, but here is an interesting sample : If we look at the history of transactions on these addresses we can see that in a lot of cases, a few seconds after money was deposed in them, it was withdrew to another account.

In particular, it was often sent to one of these accounts : 1brain7kAZxPagLt2HRLxqyc3VgGSa1GR 15LPodNPGv5qsKPc4PUfyeJKdDReWjCknS 1mineraceNChe36ftTXU5Y8EvypyM3iu8 We can see that the first address already stole 0.36 Bitcoins, 2 seconds after they were transferred to the address corresponding to the key « alfanumerico » !This address seems to contain more than 1 Bitcoin, probably stolen all automatically... Notice that the address starts with « brain », maybe it could have something to do with Brainwallet, no ?Another interesting fact, the second address stole very tiny amounts of money from classical addresses, and we can even see that a comment was left about one of these transactions : A Bitcoin theft that left a comment to another, advising him to stop stealing tiny amounts of money and wait for bigger amount on more difficult addresses... Technical considerations To bruteforce Bitcoins like that, you need to find the address associated to a private key, as fast as possible.

But, you will also need to know if each of the address was already used in a transaction.For that, you will need to iterate trough the entire blockchain.You can then fill a Bloom filter with every address seen in it.Once it is built, you will be able to know if an address was used in the network with a really small lookup time.As we have seen, it seems that some people even built a gigantic database, mapping from “classic” addresses to their associated private keys.They seems to be able to steal money only seconds after it was deposited... Conclusion Well, it seems that there is money to make, and here is the proof that some people are already on it... This also demonstrate that you can use a service like Brainwallet, but you need to choose a really strong passphrase, that will resist bruteforce.If any computer or any other human can think of it, you are doomed !Instead of attacking every potential transaction that used a weak private key, it’s also possible to focus on weak random number generators, or implementation problems in ECDSA.