Hot answers tagged

8

A deanonymizing dust attack works by sending dust to large amounts of addresses. The assumption is that when people send transactions/perform consolidations in the future, dust from multiple addresses will be grouped into a single transaction, thus revealing many addresses controlled by a single entity, since the dust would be swept in a single tx. (this ...


8

TCP and other stream based protocols do not have a 1-to-1 correlation of application level messages and IP packets. If you call send() 3 times, it might result in sending a single IP packet over the wire (eg, due to Nagle's algorithm which is enabled by default), it might get sent individually as 3 packets, as you would expect from a packet oriented protocol ...


6

In Confidential Transactions (as used in Blockstream's Elements and Liquid), there are still identifiable UTXOs. The only change is that instead of the amount, a homomorphic commitment to the amount is stored. While not technically correct, you could see it as a form of encryption that is compatible with addition and subtraction. So if a+b=c+d then E(a)+E(b)...


6

Your address is a classical 1 (Pay-to-public-key-hash) address. Your friend has a newer Bech32 Pay-to-Witness-public-key-hash-type address. The block explorer you referenced is partially compatible with Bech32. Sometimes, it doesn't work. On the other hand, there's nothing that prevents you from looking at your friend's transactions using a different block ...


4

To add to Raghav's answer: Practically, as a typical user, it can be difficult to deal with a dust attack. There is no way to stop or disallow the receiving of a transaction, so the user can only react to the attack after it has occurred. The good thing is, by taking the proper actions a user can easily and effectively mitigate against the attack. In a ...


3

The paper you link to when used as advice rather than a scholarly investigation into the tradeoffs of different choices is outright bad advice. The attacks they give are largely generic and have little to do with tor itself, while use of tor provides non-trivial protection against many other vectors, and if used consistently and exclusively at least ...


3

I suggest we say channel balance instead of channel state (the state is encoded by a signed commitment TX and if it leaks you could loose your funds) As for the balance such a dilemma indeed exists. Indeed routing becomes more trial and error without public channel balances. Yet, there will probably be methods that allow to predict routes with higher ...


3

Channels do not publicly announce their balance for several obvious reasons It would be a huge privacy concern if balances could be viewed live on the network. People could monitor large parts of the network and aggregate data about how balances change over time, which could then be used to trace payments through the network and deanonymize users. If every ...


3

Zerocoin is a proposed extension on Bitcoin to make Bitcoin more private. Zerocoin only hides the origin of a payment, the destination and amounts are still public. Zerocash is a further extension of the zerocoin protocol which hides the destination and amounts. Zerocash transactions are more compact than zerocoin transactions. Zcash is an implementation ...


3

Does it affect -most importantly- the safety of the funds? It does not. Funds are not affected by publishing a LN invoice. Does it negatively affect the privacy or something else? If a lightning invoice is published, 3rd parties may learn some semi-private information about the payer and payee. First and foremost, they learn the amount that was paid and ...


3

What is the reason? And Is it logical to use "Proof-of-Authority" for a "public" blockchain, in sense of keeping decentralization? Proof of Authority is, by definition, centralised. If the authority nodes go rogue, or fail to reach consensus, the network is useless. You could use it in public networks (some of the ethereum testnets are PoA), but it would ...


3

Bitcoin is not yet built with a privacy layer, all transactions are public and immutable, meaning they are visible to everyone, everywhere, forever. If you wish to make a private transaction, you are better off using another blockchain like Monero, Zcash, or one of the many others focused on maintaining user privacy.


3

Assume you are using a unique common address for each customer and at the end of the day/week/month you make payments to your employees, suppliers or partners. When making those payments, if those outgoing amounts exceed the amounts received from one customer, you will have to include inputs coming from other customers. If some of your customer addresses ...


2

Regardless of the maximum size of a single transaction, a CJ anonymity set can be made arbitrarily large (bounded, of course, by participants) by building a multi-stage switching network out of joins. This was described in the original coinjoin post: In particular, if you can build transactions with m participants per transaction you can create a ...


2

IP addresses are not private information. As for email and name no one can get that information based on the blockchain data alone unless you go out of your way to publicly associate your identity with a specific address. For example by mentioning your email, name and address together on some website. Another possibility is that you reveal your identity to ...


2

The channel balance is not a public information. If you look at the channel_announcement-message in BOLT7 you see that the following information of the channel is public: [64:node_signature_1] [64:node_signature_2] [64:bitcoin_signature_1] [64:bitcoin_signature_2] [2:len] [len:features] [32:chain_hash] [8:short_channel_id] [33:node_id_1] [33:node_id_2] [33:...


2

With option 2, most analyses will conclude that Alice owned A1, A2 and A3, because the transactions which spent them have no change address. Typically, you assume that the amount you have held in a TXO never exactly matches the amount you're making as a payment, so transactions usually have change outputs too. I think you have a little misunderstanding ...


2

Can this effectively be used to break/hide a Bitcoin transaction chain? No, the block explorers you've mentioned simply do not include code that is capable of decyphering the nonstandard transaction you've linked to. Importantly: Bitcoin transactions do not include a 'from address', instead they reference a valid unspent transaction output (UTXO) that ...


2

HD vs non-deterministic: "HD" means "hierarchical deterministic". "deterministic" means: all private keys are generated from a seed, "knowing the seed = knowing all the private keys", so that frequent backup is no longer needed. "hierarchical" means: you can manage multiple coins/accounts/address types with only one seed. Watch-only wallets are supposed ...


2

In lightning network payments are onion routed. The only thing a PSV could reveal is the previous and next hop, but they can not know the origin or the destination. They know it came from Alice, and went to Bob, but they do not know where Alice may have gotten it from, or where Bob may send it to.


2

To add to Rene’s answer: The protocol design currently allows the probing of viable paths to leak just enough information to let you determine whether all channels along route provide adequate liquidity or not, without revealing the individual channel balances. Note though that one could use probing (receiver and sender controlled by same individual) with ...


2

Actually, the BOLT has been designed with very strong privacy properties with regard to watchtowers. You can give all your commitment tx id first halves to one watchtower and it still doesn't learn anything about the second halves, others txs or anything else about the state of the channel (or which channel it is watching at all), as long as the full ...


2

Currently, best practices are to receive coins to an address only once - Any reasonably new wallet will generate a new receiving address for you if the previously displayed one has already received coins. However, there are scenarios where an address might receive coins multiple times, such as being a saved address on an exchange, stored with an automatic ...


2

Using a mixer helps preserve your financial privacy. The question is: who are you protecting your privacy from? Bitcoin transactions are public record, so anybody can view any historical transaction at their leisure. So when considering your privacy, there are a few different situations worth exploring, for example: An unrelated third party is looking at ...


2

I am not sure if I get your question right. Please tell me if not and I shall iterate on my answer. First of all the lightning network indeed has a different privacy model only opening and closing of channels is stored to the redundant public ledger called blockchain. Once the channel is open even when routing is applied the payment itself is pretty private....


2

...does this present a privacy risk? Privacy concerns can be boiled down to the following questions: what information am I giving up by engaging in this transaction? And who am I sacrificing this information to? When you engage with some counterparty to make a payment, they will gain knowledge about your involvement in the bitcoin transaction that includes ...


1

The Lightning Network does not have the same problems as Bitcoin because all communication is done over an encrypted and authenticated protocol. Lightning Nodes are identified by their public keys, such that communication only occurs between somebody with the matching private key to the public key expected by the connection initiator, making MITM attacks not ...


1

Sidenote: bitcoins exist as unspent transaction outputs (UTXOs), so with this in mind the two options you outlined for Alice create two different situations: in situation 1, Alice will have one UTXO. In situation 2, Alice will have 3 UTXOs. The question you've asked involves an analysis of UTXOs, so I thought this was worth mentioning. Can someone ...


1

In a transaction bitcoin, there is not information on the recipient, right? Correct, the address/script that the payment is sent to does not have any user or wallet-identifying information included in it. How do services such as blockchain.com track information about a transaction, from which wallets have they started and to which wallets have they ...


1

Block explorers know some information about wallets because they belong to public entities with known addresses. Other wallets are known because Bitcoin wallets typically follow a spending pattern where it's very easy to link together outputs and inputs belonging to the same wallet. For example: in most transactions all inputs belong to the same wallet ...


Only top voted, non community-wiki answers of a minimum length are eligible