- CJ is decentralized opensource based on P2P agreement on inputs and outputs
- really huge joint transactions would not be wise
3.increasing the number of transactions. the more users the more anonymous - No need for a soft fork
1 Like
Thanks Alko89, that cleared things up a bit 
1 Like
1.)
Coinjoin is no centralized service.
No counter party risk involved.
2.)
Reasons for the failure of a coinjoin transaction:
- DOS attack
- A participant does not sign the transaction
3.)
by increasing the number of transactions in the coinjoin transaction.
4.)
There is no fork of the Bitcoin protocol is necessary.
They are indistinguishable from normal transactions and thus cannot be blocked or inhibited except
to the extent that any other Bitcoin transaction could be blocked.
1 Like
DOS in coinjoin basically is when someone doesn’t sign. Preventing others to send the joint transaction to the network (Denial Of Service)
2 Likes
1.bitlaundry was centralized servioce with good idea but great deal of trust in bitlaundry providers.
2. Failure retry risk is when a transaction fails because an input/output pair are invalid. It could fail due to several reasons such as attack or other party not signing or spending their input before that is completed.
3. build transactions with m participants per transaction you can create a sequence of m*3 transactions which form a three-stage switching network that permits any of m^2 final outputs to have come from any of m^2 original inputs (e.g. using three stages of 32 transactions with 32 inputs each 1024 users can be joined with a total of 96 transactions). This allows the anonymity set to be any size, limited only by participation.
4. Zerocoin requires a soft-forking change to the Bitcoin protocol , which all full nodes must adopt, which would commit Bitcoin to a particular version of the Zerocoin protocol. This cannot happen fast—probably not within years, especially considering that there is so much potential for further refinement to the algorithm to lower costs.
1 Like
- When you want to make a payment, find someone else who also wants to make a payment and make a joint payment together. Doing so doesn’t increase privacy much, but it actually makes your transaction smaller and thus easier on the network (and lower in fees); the extra privacy is a perk
2.The risk is of the transaction to fail because of a DOS attack or because a participant of the transaction doesn’t sign his part. - if you have can build transactions with m participants per transaction you can create a sequence of m*3 transactions which form a three-stage switching network that permits any of m^2 final outputs to have come from any of m^2 original inputs (e.g. using three stages of 32 transactions with 32 inputs each 1024 users can be joined with a total of 96 transactions). This allows the anonymity set to be any size, limited only by participation.
- a)Zerocoin requires a soft-forking change to the Bitcoin protocol , which all full nodes must adopt, which would commit Bitcoin to a particular version of the Zerocoin protocol
b)CoinJoin transactions work today , and they’ve worked since the first day of Bitcoin.
c) it used more established and trusted crypto techniques
d) smaller sigantutres
e)faster validation
1 Like
-
bitlaundry is centralized. coinjoin is decentralized and needs users to agree on a set of inputs to be spent, and a set of outputs to be paid. they are then signed individually and joined at the end.
-
The risk of some participants “going down” during the process of Coinjoin or the possibility of DOS attack.
-
by increasing the number of transactions even further.
-
a soft-fork isn’t needed like with Zerocoin.
1 Like
-
What is the benefit of CoinJoin over BitLaundry, if any?
is not centralized but is agreed by users which can sign only if the tx is correct, no scam possible -
About halfway down, Maxwell writes: “failure (retry) risk mean that really huge joint transactions would not be wise.” Explain failure (retry) risk.
one user don’t sign the tx so it has to be “organized” a new one -
How can anonymity set be increased while keeping small transaction sizes?
making higher number of tx -
What is the main benefit of CoinJoin over Zerocoin?
zerocoin require a soft fork while coinjoin doesn’t
1 Like
1.) What is the benefit of CoinJoin over BitLaundry, if any?
CoinJoin is decentralized while BitLaundry is centralized.
2.) About halfway down, Maxwell writes: “failure (retry) risk mean that really huge joint transactions would not be wise.” Explain failure (retry) risk.
Failure risk is related to the risk that the CoinJoin transaction fails because of a DOS attack or because a member of the transaction is not able/willing to perform its part of signature.
3.) How can anonymity set be increased while keeping small transaction sizes?
By increasing the number of transactions.
4.) What is the main benefit of CoinJoin over Zerocoin?
The main benefit of CoinJoin is, it doesn’t require a soft-fork such as Zerocoin.
1 Like
-
BitLaundry is centralized whereas CoinJoin is decentralized
-
Failure (retry) risk means a transaction fails because of a DOS attack by someone refusing to sign a valid transaction, or someone spending their input out from under the joint transaction before it completes
-
The anonymity set can be increased while keeping small transaction sizes by increasing the number of transactions
-
The main benefit of CoinJoin over Zerocoin is that it does not require a soft fork
1 Like
1.- Coinjoin is a P2P protocol while Bitlaundry is a centralized mixer coin.
2.- Failure risk is related to the risk that coinjoin tx fails. Because of Dos attack or because someone of the tx doesn’t want to perform the tx and the coinjoin needs all signatures of the group.
3.- By increasing the number of tx in the process.
4.- Coinjoin is working without modify any BTC protocol… Zerocoin needs a soft fork to be implemented. It requires more computing power and technical resources.
1 Like
- Users need to agree on a set of inputs to be spent and a set of outputs to be paid. Then, individually sign their own transaction and later merge their signatures. This is CoinJoin!
- the risk of a failure is that the CoinJoin transaction fails, which can be found in two reasons A a DOS attack or B. A member is unwilling to sign the transaction. There is always a higher risk when it comes to large transactions. This leads to a risk for all parties involved.
- Number of transactions needs to be increased.
- Soft fork is not required for CoinJoin.
1 Like
There is no central service needed. Only the users who agree on inputs are in the middle.
Users are not willing to sign ore a DOS attack.
More inputs.
No soft fork needed.
1 Like
CoinJoin
- What is the benefit of CoinJoin over BitLaundry, if any?
- CoinJoin is more “decentralized” as it requires a set of people to agree to mix their inputs (p2p)
- About half way down, Maxwell writes: “failure (retry) risk mean that really huge joint transactions would not be wise.” Explain failure (retry) risk.
- Failure risk is related to the risk that the CoinJoin transaction fails, When one party does not want to sign a transaction, when there is an attacker, etc that makes one input/output pair to fail. This puts all the other participants of the network at risk.
- How can anonymity set be increased while keeping small transaction sizes?
- By increasing the number of cascading small transactions. More transactions = more anonymity
- What is the main benefit of CoinJoin over Zerocoin?
- CoinJoin= no fork of BTC, Zerocoin does require a soft forking change to the protocol
1 Like
1 A possible benefit might be no delay. But the time and effort to find the others to join the transaction may exceed this plausible upside.
2 Failure of a transaction by one or more of the participants not signing the transaction can be a problem. Also there is always some time of delay, during anyone part of the intended transaction might try double spend. The larger the amount, the more certain you want to be nothing disturbs the transaction so that is two reasons why this will not work in general.
3 At the time of this blog post, transaction fees was small, so by increasing the number of inputs and outputs the anonymity set can be increased without too much downside.
4 CoinJoin is a procedure of action, ZeroCoin is a change of the Bitcoin protocol by a soft fork. So CoinJoin can be applied as things are without any involvement of the whole community. Not implementing ZeroCoin you may rely on more secure cryptography.
1 Like
- Bitlaundry is central and trust is required, coinjoin can be done without trust in a decentralised network.
- The risk that the tx fails because one or more of the parties do not hold up their end of the bargain.
- By increasing the amount of transactions.
- You can use coinjoin on the existing BTC system.
1 Like
- While BitLaundry is a centralized third party working as an intermediary in the transaction between two users, the use of CoinJoin happens voluntarily between users that can choose to use this mechanism. Also, CoinJoin transactions are “externally indistinguishable from a transaction created through conventional use”, while transactions that rely on BitLaundrey will be easily recognized.
- Failure risk is related to the risk that the CoinJoin transaction fails, either because of a DOS attack or because a member of the transaction is not able/willing to perform its part of signature. It is an increased risk when it comes to huge transactions because it would put at risk all other parties involved.
- By increasing the number of transactions happening within the process.
- CoinJoin already works on Bitcoin and it does not require any relevant change (even considering further developments) to its structure and protocol, while Zerocoin would require a Soft Fork to be implemented. It would also mean that members of the network could not agree with it and it could endanger the stability of the community. Also, CoinJoin is less demanding in terms of computing power and other technical aspects which are heavier on Zerocoin.
1 Like
1. What is the benefit of CoinJoin over BitLaundry, if any?
CoinJoin is not centralized.
2. About halfway down, Maxwell writes: “failure (retry) risk mean that really huge joint transactions would not be wise.” Explain failure (retry) risk.
A failure would be when a signature is unable or unwilling to be added, which stops the transaction from going through. Everyone in a large transaction needs to update their signature.
3. How can anonymity set be increased while keeping small transaction sizes?
Cascading multiple transactions.
4. What is the main benefit of CoinJoin over Zerocoin?
It is available now and does not require a soft fork.
1 Like
-
What is the benefit of CoinJoin over BitLaundry, if any?
A)The benefit of CoinJoin over BitLaundry is that BitLaundry is centralised and involves a third party, whereas with CoinJoin the users validate the inputs and outputs themselves. -
About halfway down, Maxwell writes: “failure (retry) risk mean that really huge joint transactions would not be wise.” Explain failure (retry) risk.
A) Retry gives the opportunity for the sender to withdraw the funds or not sign the transaction. -
How can anonymity set be increased while keeping small transaction sizes?
A) Anonymity can be increased by increasing the number of transactions -
What is the main benefit of CoinJoin over Zerocoin?
A) Zerocoin needs a soft fork to change the protocol and Coinjoin does not.
1 Like
1.- Conjoin is decentralized by default, encouraging users to agree on inputs and outputs and merge their signatures after the Tx is signed. BitLaundry is centralized, therefore, you need to trust the middleman providing the service.
2.- In this case, the risk is that the other party will finally not sign the transaction because he does not will to or he suffers a DoS attack, so your transaction will neither be able to be done.
3.- By increasing the number of transactions.
4. CoinJoin doesn’t require soft fork, while ZeroCoin did.
1 Like