DASH - Reading Assignment

[CC123]

1. The history of the utxos, by a variation of coinjoin.
2. By breaking your utxo into set parts
3. By hacking the masternode.
4. You have to trust the masternode

[massam78]

1. PrivateSend This function allows you to hide the details of an operation in addition to the information about who issues and who receives a payment. This is due to the fact that this function makes a “mix”of the transactions, which makes tracking difficult. This function provides a “real” financial privacy,when reserving the origin and destination of the funds. The method used is called coin-mixing.
2. In order to be able to carry out this coin-mixing within a transaction, the total amount to be sent is divided into several partial amounts of identical sizes, each of which is assigned to its own address. The sender’s wallet software now selects a master mode and makes a transaction request for the total amount, submitting the subtotals. The masternode then joins with 2 other master nodes, since 3 Masternodes are required to complete a PrivateSend transaction, and mixes the subtotals of other PrivateSend transactions together. Before the transaction of the total amount, which is made up of “new” subtotals of other PrivateSend transactions, is transmitted to the recipient, the sender’s wallet software checks whether the total amount is still correct. If so, the transaction is performed. The more of these coin mixing rounds the broadcaster requires, the harder it will be to track the movement of the coins on the blockchain.
3. It is only possible If a single entity has the ability to control or spy on a portion of DASH’s masternodes, it’s entirely possible to reverse engineer PrivateSend transactions to reveal origin and destination details.4.In a PrivateSend transaction, the sending and recipient addresses are always transparent, as is the amount sent. Furthermore, PrivateSend transactions can be analyzed, and although an individual transaction’s origins can only be identified with probabilities, patterns over time can be determined and incorporated into risk scoring models just like in Bitcoin, in fact, in the same exact manner as Bitcoin.

[carolb]

1. What information does PrivateSend conceal, and by what method?
   A) Hides the details of a transaction by using CoinJoin, it is not possible to see who the sender and receiver are.

2. How do masternodes improve on the initial CoinJoin proposal?
   A) The masternodes automatically mix the coins up, therefore they can not be distinguished

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
   A) The attacker could link the addresses by connecting to the masternode. highly unlikely.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
   A) You have to have trust in the Masternodes. The Masternodes could be operated by malicious entities.

[Criptocabro]

@Grant_Hawkins

• What information does PrivateSend conceal, and by what method?
• How do masternodes improve on the initial CoinJoin proposal?
• Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
• In what way could PrivateSend be more risky than a normal Bitcoin Transaction?

1.- It hides to some extend who has sent the cryptos by adding together coins sent from several users.
2.- Masternodes are in charge of collect and mix the coins, instead of the user itself, thus, being many masternodes, it is a decentralized version of it.
3.-The mixing masternodes can link the sending and receiving addresses together, so the attacker need to exploit the masternode or be him.
4.- If a masternode is compromised and also the fact of using the private choice makes you suspicious and targeteable since before that your privacy is not as good.

[markyb]

1. The origins of your funds by mixing your inputs with the inputs of at least two other people in a single transaction.

2. Through a decentralised implementation of CoinJoin.

3. If the mixing process is compromised.

4. The masternode could be run by bad actors.

[PapatoniC]

1. What information does PrivateSend conceal, and by what method?
   Input addresses. They are mixed between different people.
2. How do masternodes improve on the initial CoinJoin proposal?
   They never know who you are.
3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
   The attacker should also know the others participants addresses.
4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
   I dont think there is more risk

[Alko89]

@PapatoniC

I dont think there is more risk

It can be in case of a malicious MN that would expose the mixed addresses.

[PapatoniC]

Thanks Alko89 , so then i understand there is more risk of malicious MN compared to a possible malicious Bitcoin nodes , isnt it?

[Alko89]

@PapatoniC

MN compared to a possible malicious Bitcoin nodes , isnt it?

Hmm, I guess it depends on the type of the Bitcoin node, what has been modified. This is only the case if you’re using a strange SPV wallet that connects to that node. A malicious node can’t do much damage in the network itself so in this regard I would say a malicious MN is more risky because you don’t really have control what MN to use while in case of a Bitcoin node, you can just use a different wallet.

[PapatoniC]

Sure make sense thanks for clarifying !

[Sebas]

@Grant_Hawkins

• What information does PrivateSend conceal, and by what method?
• How do masternodes improve on the initial CoinJoin proposal?
• Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
• In what way could PrivateSend be more risky than a normal Bitcoin Transaction?

1. It breaks the link between sender and receiver of the transaction by splitting the amount into denomination categories and then perform several rounds of coinjoin.
2. It is a more automated user experience since the masternode organizes everything: Improvements to Coinjoin: several fixed denomination categories, several rounds of coinjoin.
3. If a masternode it compromised, they could link sender and receiver.
4. less decentralisation through the masternode system.

[Rigel12]

1. What information does PrivateSend conceal, and by what method?
   It conceals the origin of your funds. It does this by mixing your inputs with the inputs of at least two other people in a single transaction.

2. How do masternodes improve on the initial CoinJoin proposal?
   They automatically construct the transaction.

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
   If the attacker had access to the masternode they could link the addresses.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
   Choosing a private transaction could flag someone as having something to hide.

[Nelson1]

1. What information does PrivateSend conceal, and by what method?
   PrivateSend gives you true financial privacy by obscuring the origins of your funds

2. How do masternodes improve on the initial CoinJoin proposal?
   Your wallet then sends requests to specially configured software nodes on the network, called “masternodes”. These masternodes are informed then that you are interested in mixing a certain denomination. No identifiable information is sent to the masternodes, so they never know “who” you are.

When two other people send similar messages, indicating that they wish to mix the same denomination, a mixing session begins. The masternode mixes up the inputs and instructs all three users’ wallets to pay the now-transformed input back to themselves. Your wallet pays that denomination directly to itself, but in a different address (called a change address).

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.

An attacker has no way of linking their addresses because No identifiable information is sent to the masternodes, so they never know “who” you are.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?

Knowledge of the exact number of rounds of PrivateSend mixing used in any given PrivateSend transaction has a quantifiable effect on the confidence an adversary may have when attempting to guess the source of a PrivateSend transaction. For this reason, the recommended (and default) number of rounds of PrivateSend mixing is set to four, and some inputs may be mixed by additional rounds to further improve privacy.

[Lucena7]

1. What information does PrivateSend conceal, and by what method?
   By using the method of CoinJoin, users’ addresses and amount of transactions through coin mixing by masternodes.

2. How do masternodes improve on the initial CoinJoin proposal?
   Masternodes automate the process of mixing coins, avoid relation between inputs and outputs to be identifiable.

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
   If the attacker runs the masternode he knows the sender’s address and the recipients address.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
   Masternodes can be operated by malicious entities, governments or other third parties.

[andor]

1. the origin of the coins. when you initiate a PrivateSend, basically you send the coins to a master node - the master node will identify at least 2 more users interested in PrivateSend - then the coins of the 3 participants will be mixed - then you receive the coins back to a newly generated “change” address. this of course all happens automatically and pretty much instantly so the value of your Dash will never leave your wallet
2. CoinJoin is a p2p service while Master Nodes are operating in a similar way as miners on the Bitcoin network (they are just supplying computing power for a reward and the code/program does the actual mixing)
3. it’s only possible if the majority of master nodes are taken over by the same attacker/entity. then they could potentially see the IP addresses from where the coins been sent from as well as the original wallet addresses
4. using the PrivateSend feature may raise suspicion (as well as any other coin mixing service)

[fabianvon]

What information does PrivateSend conceal, and by what method?
PrivateSend gives you true financial privacy by obscuring the origins of your funds

How do masternodes improve on the initial CoinJoin proposal?
The masternode mixes up the inputs and instructs all three users’ wallets to pay the now-transformed input back to themselves. Your wallet pays that denomination directly to itself, but in a different address (called a change address).

Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
While it is not possible to link a PrivateSend transaction to a single source address with absolute certainty, using more inputs may make a transaction more vulnerable to different potential linking attacks.

In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
You have no real say in the Mixing process other than the number of mixes

[BeeTeeSee]

1. PrivateSend conceals the source of transactions. It accomplishes this by mixing the inputs from several similar transactions all at the same time via its masternodes.

2. Masternodes improve on CoinJoin by networking and organizing parties who want to do a private transaction, instead of requiring the users to find each other on their own.

3. If an attacker can access the info from a masternode, he/she could potentially learn about the identity of participants in transactions.

4. It can be more risky than a normal Bitcoin transaction if the masternode is being used maliciously, thus it requires trust in said masternode.

[Jesal_Patel]

1. What information does PrivateSend conceal, and by what method?

PrivateSend conceals information in regards to where your funds originated from. This is done by mixing your transaction inputs with two other people’s after the inputs have been broken up into denominations e.g.(0.001, 0.01, 0.1, 1 and 10 DASH) like paper money. The mixing may apply 1-16 times and the more times it is applied, the more difficult it becomes for any third-party to reveal the identities behind those transactions.

2. How do masternodes improve on the initial CoinJoin proposal?

They construct the transactions and provide anonymity via mixing with only two other participants. This way anonymity can be achieved via mixing without having to add transactions from more than two other participants which can lead to failures such as retry- (Correct me if I’m wrong)

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.

Considering mixing of transactions would generate a new ‘change address’ each time in which they would pay to…the attacker can still reverse-engineer the original sender and receiver of a transaction by querying the blockchain.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?

A master node could act maliciously on the network to compromise the anonymity of its users.

[LilKnownFact]

1. What information does PrivateSend conceal, and by what method?
   PrivateSend conceals the origin of your funds by mixing your inputs with the inputs of at least two other people in any transaction.

2. How do masternodes improve on the initial CoinJoin proposal?
   CoinJoin involves the separate parties having to communicate directly, while the masternode facilitates the coin mixing.

3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
   A masternode can be spied possibility if it is on a private network.

4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
   It introduces trust into the equation via the owner of the masternode. That owner is also a targetable point of weakness.

[MosesCruz22]

1. PrivateSend masks the input and outputs much like CoinJoin.

2. The “mixing” of inputs by 3 other inputs keep the anonymity between the transactions

3. A Masternode would be the one who “gave up” such information. Whether at their own will or through an attack

4. The network isnt as large enough AND pre-determine attackers couldve “jumped” on such a new technology that they control or are a bigger percentage of Masternodes in circulation.