Questions tagged [privacy]

Questions regarding the information that is leaked through cryptocurrency transactions or related processes, when subject to analysis and attempts of identification of sources and other properties.

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62
votes
9answers
27k views

How anonymous are Bitcoin transactions?

I read some sources that say Bitcoin transactions are anonymous, some that say they are semi-anonymous, and some that say they are not anonymous at all. In what ways are the transactions anonymous ...
41
votes
4answers
47k views

How do I see the IP address of a bitcoin transaction?

How do I see the IP address that someone used to send or receive bitcoins with? Is it stored in the blockchain?
38
votes
3answers
14k views

What is a stealth address?

Stealth addresses are mentioned in the context of privacy of bitcoin transactions. What are they and how would they work? Can they provide 100% anonymity?
37
votes
5answers
6k views

How can one remain relatively anonymous while using Bitcoin?

Bitcoin transactions are pseudo-anonymous. What can an individual that uses Bitcoin do in order to remain as anonymous as possible?
35
votes
9answers
20k views

How is it possible to launder bitcoins?

Some services, such as bitcoinlaundry.com, claim that they can launder your bitcoins. Since all bitcoin transactions are publicly logged, how is this done? Wouldn't it be possible to trace back the ...
32
votes
4answers
7k views

Are there any _true_ anonymous cryptocurrencies?

I've been looking into Bitcoin recently and stumbled upon numerous notes how Bitcoin is not anonymous at all, or how it's only partially anonymous and you can easily trace your funds. So, this ...
26
votes
4answers
8k views

What are tainted coins exactly?

I've come across the term of a tainted coin several times now. I understand that coins, or better, the origin of a coin can be traced throughout the blockchain. I've read that bitcoins can be ...
25
votes
7answers
19k views

What Bitcoin Mixing/Laundry Services are availble today?

A Bitcoin Laundry or Mixing Service is a service that accepts BTC payments, and returns the same BTC amount, only from coins that are unassociated to the original BTC. It is a privacy service that ...
17
votes
9answers
1k views

Is there any way the Bitcoin network could resist a viral tainted-coin tagging system implemented by regulators?

Already it's possible for MtGox etc. to detect spends of coins that have certain well-known thefts in their history. If regulators forced audits on exchanges and key popular merchants, as well as ...
17
votes
3answers
27k views

Knowing a single transaction can you track down a Bitcoin user?

I have used this transaction to donate to Wikileaks. I have applied no special techniques to obsure my identity. How much information can find out about me on the blockchain. What tools would you use? ...
16
votes
2answers
4k views

Are Monero Transaction Anonymous?

Lets say i have a monero address and want to send my coins to another address. Will that transaction be private? Can somebody find out that i sent those coins? Are there any altcoins that i can use to ...
16
votes
2answers
1k views

Does the ZeroCoin protocol fulfill its promise of anonymity?

Zerocoin is a new cryptographic extension to Bitcoin that (if adopted) would bring true cryptographic anonymity to Bitcoin. Has anyone seriously analyzed the protocol and verified it works as ...
15
votes
9answers
32k views

How can I hide my bitcoin transactions to protect anonymity?

I read many related questions about the pseudo-anonymity and bitcoin transaction tracking. So if I understand correctly, bitcoins, or better, transactions can be tracked for their entire lifetime. ...
14
votes
2answers
2k views

Is my account balance publicly visible?

If I'm sending someone my wallet address, am I making my account balance visible to him? As far as I understand, all transactions are public, which means that if I know an address, I can reconstruct ...
14
votes
7answers
4k views

Are bitcoins INHERENTLY fungible?

Does each bitcoin has a unique identifier, like currency notes have serial numbers? If so, could you trace a particular bitcoin's ownership chain (ie find the current owner of a particular bitcoin by ...
13
votes
2answers
294 views

What are the privacy implications of filtered blockchain downloads?

There is now "Bloom filter" support in the network protocol for sending only relevant transactions to lightweight clients. What are the privacy implications of the bloom filter? Does it leak any ...
11
votes
3answers
194 views

Privacy friendly payment processor

What is the most reputable Bitcoin payment processor that has privacy friendly terms and conditions? BitPay and Coinbase are known to have used chain analysis to spy on customers. What are the ...
11
votes
2answers
790 views

Anonymity through paying by bitcoin

I am considering the VPN service Privateinternetaccess. One of it's payment methods is bitcoins. As described on this page paying with bitcoins strengthens anonymity. In contradiction, this page ...
11
votes
4answers
704 views

Does the bitcoin block contain minimal transaction detail? (Is it as private as possible given the proof-of-work design?)

From https://crypto.stackexchange.com/questions/508/could-one-prevent-double-spending-in-decentralized-digital-currencies-like-bitc "Now, the only information about the transaction that needs to be ...
10
votes
4answers
3k views

Explain how CoinJoin enhances anonymity, in plain English?

I just learned about CoinJoin, but I don't really understand all the jargon being thrown around. Can someone explain how this works where a 10-year-old can understand?
10
votes
2answers
648 views

Can I hide my IP address by blocking incoming connections in the client?

I know that it is possible to find out the IP address of a transaction by connecting the client to every node in the network. Dan Kaminsky wrote: When you are connected to every node, the first ...
10
votes
3answers
2k views

Which exchanges are Tor-friendly?

Mt. Gox's sign-up page states: Please be advised that accessing your account via the Tor network and/or public proxies may result in a temporary suspension of your account, and having to submit ...
9
votes
3answers
609 views

How can I control which coins to spend in a transaction?

When creating a bitcoin transaction, you have to choose which coins to use in them. The standard client does this in a way to avoid unconfirmed inputs and minimize the number of inputs and amount of ...
9
votes
1answer
3k views

Should I use a different address for every transaction?

Should I use a different address for every transaction? If yes, why? For safety? What happens I use the same address to get bitcoins from 2 different people, what happens?
9
votes
1answer
111 views

Bitcoin node Decentralization

Is the number of independently owned and operated full Bitcoin nodes more important than the total number of full Bitcoin nodes with regards to Decentralization? Assuming the answer to the above ...
9
votes
2answers
1k views

Is there an easy way to search all the transactions?

Is than an easy way to search the list of all bitcoin transactions? For example to find all the bitcoins sent to or from an address?
8
votes
2answers
1k views

Why is the ledger public?

To me, banking is not a public thing. I don't want people to know what's in my bank account at what time, or who I sent money to. I know that I can make a new address for each transaction, as ...
8
votes
3answers
236 views

What is the most advanced technology for anonymous transactions?

What is the most advanced technology for anonymous transactions feature? I’ve heard about zerocash and coinjoin but which one of them has a technological edge? Are any of these technologies really ...
8
votes
1answer
1k views

What is BlitCoin?

I saw BlitCoin mentioned on this forum thread, but didn't understand what it was. Can someone explain what does it do?
8
votes
2answers
190 views

Confidential Transactions on main chain

I have seen discussion of CT being used on the a side chain. What are the chances it will be applied to Bitcoin Core itself?
8
votes
3answers
2k views

Does sending from a green address improve my anonymity?

If I am interested in improving my anonymity when dealing with a merchant, does sending from a Green Address help? My proposed steps for buying from a merchant as anonymously as possible would be: ...
8
votes
1answer
1k views

Procedure for calculating taint?

I'd like to understand taint analysis quantitatively. Blockchain.info offers a service that will calculate taint, but I've found no good explanation for how taint is calculated. The best (and only) ...
8
votes
2answers
8k views

Is it possible to view others' transactions in bitcoin client?

This seems like a really basic question, but I'm having trouble searching for answers on it. My understanding is that my bitcoin client (Bitcoin v0.7.1-beta) has basically theoretically downloaded the ...
8
votes
3answers
5k views

Best way to mix bitcoins? mixer, coin join (shared send), dark wallet, stealth addresses?

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: ...
8
votes
1answer
243 views

Bitcoin privacy metrics?

I'm looking for a numerical privacy scoring system that estimate the degree of linkage between the members of a key pool (or even just individual key pairs). Ideally, the method should be easy to ...
7
votes
1answer
261 views

Bitcoin Node Data Leakage

Besides an IP address and broadcasting transactions, what other pieces of information can be derived from a Bitcoin node in the network?
7
votes
3answers
3k views

Sending Bitcoins through Tor versus sending them through VPN

I bought a VPN subscription using Tor and Bitcoins. The commercial VPN service provider does not know who I am. Below are my questions: Could someone tell me whether sending Bitcoins through Tor ...
7
votes
1answer
199 views

What metadata can be captured by a single miner? What about a group of miners?

It is my understanding that the blockchain consist of the following information for every transaction in the network: From address To address Amount of bitcoins What additional information can a ...
7
votes
2answers
433 views

For lightning network, can I surround myself with a bunch of nodes to increase anonymity

Let's say I'm on a lightning network. Can I create a bunch of nodes, and do all my spending through those nodes? Can you hide the fact that these nodes are likely controlled by the same person? How ...
6
votes
1answer
129 views

Why is the length of the transport messages on the lightning network encrypted?

From BOLT 08 we can see that every message is sent in the following way: 2 byte: length 16 byte: MAC [length] byte: Encrypted message 16 byte: MAC In reality these messages will be send over TCP/...
6
votes
3answers
92 views

Why Coinjoin need other participants to increase their privacy?

Coinjoin is a method that make a transaction with other transaction of other parties to hide the link between txin and txout. In case of this, why we need others transaction? We have many bitcoin ...
6
votes
4answers
12k views

How to buy bitcoins anonymously

I'm studying the Bitcoin system and I'm wondering if there's a way to anonymously buy Bitcoin. Is it possible to charge a wallet (e.g. with a credit card, PayPal account, by person, by snail mail, etc....
6
votes
2answers
438 views

Is it possible for a decentralized currency to have untraceable transactions?

I have been reading a bit about Bitcoin recently and am fascinated with the project and think it has great potential. However, one thing I think it needs in order to gain mass popularity is to make ...
6
votes
4answers
3k views

HD wallets and address reuse

HD wallets create a series of addresses, and then when one address has received an input it will give you a new address that hasn't received inputs yet So in the idea of you sending yourself bitcoin ...
6
votes
1answer
736 views

Do thin clients leak which addresses you own?

According to this, thin clients use bloom filters to request "addresses and transactions they are interested in to the peer". And according to this, bloom filters are used to help prevent the SPV ...
6
votes
1answer
2k views

How can one be truly anonymous without mining?

Assume that person wanting to be anonymous has reason to do so. Powerful enemies will see what is bought with bitcoins, perhaps web blog on server and domain name. Even in nations with rule of law, ...
6
votes
2answers
292 views

Do bloom filters protect against a persistent eavesdropper?

As far as I understand it, bloom filters can be defined with some target hashes and false-positive rate. When filtering the blockchain, all of the target transactions are guaranteed to be found, but ...
6
votes
1answer
256 views

Vouching for (or against) the reputation of a bitcoin user

Since it's possible to link non obfuscated transactions to a "user" does is make sense, or it is possible for anonymized users with an established transaction history to "vouch" for another? I'm ...
6
votes
1answer
1k views

How to broadcast a transaction anonymously

Is it possible to broadcast a transaction to the network without revealing my personal IP address? My first guess is to connect bitcoind over Tor with proxy=127.0.0.1:9050. Is it the good way to do it ...
6
votes
5answers
2k views

Is there any way to store personal data in a blockchain?

Generally everyone can see all data stored in a blockchain. Is there any way to handle private personal data like personal medical records which only right person can see?