DASH - Reading Assignment

Read the article on DASH and its Privacy Features. Answer the questions and post your answers below:

https://docs.dash.org/en/stable/introduction/features.html#privatesend

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

4 Likes
  1. What information does PrivateSend conceal, and by what method?
    The trail of ownership of the coins. It implements the CoinJoin solution by using Dash’s Masternode system.
  2. How do masternodes improve on the initial CoinJoin proposal?
    A masternode collects the coins from different users, mixes them together in the CoinJoin Transaction
  3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    The mixing masternodes can link the sending and receiving addresses together; they know exactly which coins are going where.
  4. In what way could PrivateSend be riskier than a normal Bitcoin Transaction?
    Masternodes could be run by government agencies, spies, analytics companies and other interested parties
1 Like
  1. What information does PrivateSend conceal, and by what method?
    The link among the inputs and outputs of a transaction, it is an implementation of Coinjoin.

  2. How do masternodes improve on the initial CoinJoin proposal?
    Not requiring someone to construct the Coinjoin transaction, masternodes collect and mix the coins.

  3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    By the ammount and the time the transaction took place…or hacking the masternode.

  4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    Loosing privacy in some coins without knowing it and revealing that you once, for some reasong, wanted to use Coinjoin.
    Moreover, any aditional PrivacySend is a possibility of leaking information through masternodes…some of wich can be running in virtual private servers.

1 Like
  1. Ownership of Coins. CoinJoin principle is applied by the masternodes.
  2. A master node joins several transactions so that they can’t be distinguished.
  3. If the attacker runs the masternode he knows the sender’s address and the recipients address.
  4. You have to trust the person who runs the masternode.
1 Like
  1. PrivateSend is Dash’s CoinJoin implementation, making it possible to conceal which addresses own how many coins by mixing the coins and sending them to newly generated addresses. It is a privacy feature enabled by Dash wallets, and PrivacySend transactions are built thanks to a receiving MasterNode which mixes the transactions together.
  2. The MasterNode accepts the proposal, receives the coins from the interested parties, mixes them together and sends them to the newly generated addresses. The process can be automatically repeated up to 8 times and it involves three parties at a time.
  3. By hacking the MasterNode or by running it, since in both cases it would be easy to retrieve the information about them.
  4. If the MasterNode were run by ill-intententioned people they would have access to the information related to those parties asking for the PrivateSend service, leading to risks of exposure or other personal attacks.
2 Likes
  • What information does PrivateSend conceal, and by what method?
    they hide the trail mixing tx them togheter in a Coinjoin Tx created by the masternodes which are the only ones to know which coins are going where.

  • How do masternodes improve on the initial CoinJoin proposal?
    Like CoinJoin, Private Send require someone to construct the Tx but in this case this is done by the nodes that can’t steal the coins.

  • Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    Spying on the nodes that are going to mix their transaction, that would reveal not just that alice is sending value to bob, but also the fact that they wanted to keep it private.

  • In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    revealing the fact that the 2 parties wanted to keep a Tx private, making this result more suspicious at the eyes of the “spy”.

1 Like
  1. It hides to some extend who has sent the cryptos by adding together coins sent from several users.
  2. The masternode can’t steal the coins.
  3. If he can access the mixing transcation datas from the masternode or if the masternode is the spie.
  4. If the MasterNode were run by ill-intententioned people they would have access to the information related to those parties asking for the PrivateSend service, leading to risks of exposure or other personal attacks.
1 Like
  1. What information does PrivateSend conceal, and by what method?

It conceals the trail of ownership of the coins mixed together. It does so by implementing the CoinJoin proposal by Maxwell.

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

They improve the process by making it simpler. It’s not required that someone constructs the transaction. It’s done automatically by the masternodes.

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

Many masternodes run under a private network, so if an attacker gets access to that private network, he can get access to a considerable amount of masternodes and spy their activity. It’s also possible to run a masternode and spy its activity and link the sender and receiver addresses used in PrivateSend transactions.

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

Because many masternodes are controlled by the same entity (by running in the same private network) and we can’t really trust who is running them, the privatesend feature doesn’t look effective. In particular, spy agencies may actually collect data exactly by who is trying to preserve his privacy with the privatesend feature.

1 Like
  1. Private send hides the connection between sender and receiver just like CoinJoin.

2.The masternodes make processing of these CoinJoin transactions very simple.

  1. Run the master node that does the linking. Or otherwise get this information from masternode operator.

  2. Cryptography on with Bitcoin transaction allows to do zeroknowledge version of coin join. Also with less users then Bitcoin and then even less of those users actually using private send. DASH private send transactions could be targeted.

1 Like

1.ownership of coins, it uses a coinjoin method, implemented by a masternode of dash
2. not requiring someone to construct the transaction, masternodes do that
3.if the attcker nows address of bob and alice- if he is running masternode
4. you trust the person running the masternode. there was a large pre-mine, maybe govt is running masternode

1 Like
  1. Private Send uses the same logic as CoinJoin on Bitcoin. By mixing coins from 3 different senders Private Send conceal their addresses.

  2. They do the matching part, combining transactions of the users who have requested Private Send.

  3. An attacker could own or have a relationship with a masternode that was selected by Alice to mix coins or compromise a VPS that hosts a masternode (however, I still don’t understand how that can be done on the fly).

  4. Unlike CoinJoin, Private Send transactions are visible on the blockchain so the fact that mixing was performed may raise suspicion that users have something to hide.

1 Like
  • What information does PrivateSend conceal, and by what method?
    The address of the sender is concealed when using PrivateSender. The method of coinjoin is used.

  • How do masternodes improve on the initial CoinJoin proposal?
    The masternodes have no access to the funds.

  • Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    An attacker can obtain the private information by attacking the masternode.
    many masternodes appear to be run from virtual private servers that could be compromised relatively easily in one go, for example by government-sponsored spies. Further, many masternodes could be controlled by the same people (keep in mind that some 25 percent of all coins were mined in the first week), which means switching between them might not even help that much.
    It’s also worth noting that Private Send does require users to take the specific step of mixing, which in turn requires time, effort and comes with a (modest) fee. As such, only users who care about privacy are likely to partake in the mixing process; users who feel they have nothing to hide will not. This has the potential downside that mixing itself could be considered suspect. And while the trail of ownership is broken on the blockchain, the history of mixing is still visible.

  • In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    You need to trust the Masternodes. Using PrivateSend indicates that you have something to hide.

1 Like
  1. The link among the inputs and outputs of a transaction, it is an implementation of Coinjoin.
  2. Not requiring someone to construct the Coinjoin transaction, masternodes collect and mix the coins.
  3. By the amount and the time the transaction took place.
  4. Because many masternodes are controlled by the same entity, and we can’t really trust who is running them. Hackers could also collect data by who is trying to preserve his privacy with the privatesend feature.
1 Like
  • What information does PrivateSend conceal, and by what method?
    It uses the senders addresses and use bitcoins Coinjoin.

  • How do masternodes improve on the initial CoinJoin proposal?
    Dash users that wish to mix their coins contact a random masternode, which then collects the coins from the different users, and mashes them together in the CoinJoin transaction.

  • Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    The mixing masternodes can link the sending and receiving addresses together; they know exactly which coins are going where if these masternodes are run by spies or share their information with spies.

  • In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    Using the option Privatesend when sending DASH highlights that you want privacy and might be suspicious.

1 Like
  1. What information does PrivateSend conceal, and by what method?
    It conceals the sender of the transaction by mixing the transaction with two other users, with a CoinJoin implementation.

  2. How do masternodes improve on the initial CoinJoin proposal?
    CoinJoin normally requires someone to create the CoinJoin transaction, but this can be done through masternodes.

  3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    The masternode receives the information from Alice to send money to Bob. The masternode could be a spy, or somebody could spy on the masternode to get this information.

  4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    The user reveals that he wants privacy, while not having privacy.

1 Like
1. What information does PrivateSend conceal, and by what method?
	a. PrivateSend uses CoinJoin technique
	b. it breaks the trail of ownership on blockchain
	
2. How do masternodes improve on the initial CoinJoin proposal?
	a. the masternodes mix the coins, but they exactly know about the incoming and outgoing Txs. You must trust the masternodes regarding privacy
	b. mixing can be repeated through several nodes
	
3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
	a. if a masternode is compromised and track the input and output address
	
4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
	a. you can decide between private and public sending. the private sending may already look suspicious
	b. as mentioned above, master nodes can be compromised
1 Like

Maternodes mixes the coins of several users sending them to new addresses it has generated. Therefore nobody knows what address owns how many coins but the masternode.

  1. Due yo a privacy protocol that is build in…it mixes the transactions but does not keep track of the origin

  2. Hacking the masternodes

  3. Instant mining that happened at the launch…those masternodes could be owned by the government or an organisation with bad intentions. .

1 Like
  1. What information does PrivateSend conceal, and by what method?
    • The transaction address and amount. With coinjoining via masternodes who organize this for the participants.
  2. How do masternodes improve on the initial CoinJoin proposal?
    • You don’t have to worry about finding other participants.
  3. Alice send some DASH to Bob using PrivateSend. Describe how an attacker could link their addresses.
    • Attacker can run a master node or bribe a master node for the transaction information that is concealed only by a master node.
  4. In what way could PrivateSend be more risky than a normal Bitcoin Transaction?
    • Not only can your transaction not be private at all, you can be labelled as private transactor with something to hide, being targeted thereafter. Master nodes, although randomly chosen, need to be trusted blindly and yhey could by run to spy on the network participants.
1 Like

1- In Private Send, three users add their coins together in one big transaction, that sends the coins to freshly generated addresses belonging to the same three users. Like any CoinJoin solution, Private Send does require someone to construct the CoinJoin transaction. PrivateSend conceals the partipants’s address.

2- It’s not required that someone constructs the transaction. It’s done automatically by the masternodes.

3- Dash users must trust the masternodes with their privacy. After all, the mixing masternodes can link the sending and receiving addresses together; they know exactly which coins are going where.

4- ZeroLink framework, implemented in the Wasabi Wallet, the mixer is in this case unable to link the sending and receiving addresses. Clever cryptography helps break the link, without needing to trust anyone.

1 Like