PrivateSend and InstantSend¶
This documentation describes how to use Dash Core to send Dash privately. PrivateSend, released as DarkSend in RC4 of the DarkCoin client and rebranded to PrivateSend in May 2016, is a trustless method of running a sequence of transactions (known as "mixing") such that an external observer is unable to determine the source of funding when a PrivateSend transaction is created. This gives your Dash the same privacy properties as cash withdrawn from an ATM, for example. The mixing and denomination process is seamless, automatic, and requires no intervention on the part of the user. The current implementation of PrivateSend in the Dash Core wallet allows any amount of Dash to be mixed for later use in PrivateSend transactions. As of December 2018, PrivateSend is not currently available in other Dash wallets.
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.
You can read more about PrivateSend theory and processes here.
Open your Dash Core wallet, go to Settings and select Options. Go to the Wallet tab.
Next to PrivateSend rounds to use, enter a value between 1-16. Each round of PrivateSend performs one denominated fund mixing transaction. Higher numbers of rounds increase your overall level of privacy while decreasing the chance of detection via node collusion. 16 is the highest number of rounds currently available.
NOTE: To prevent system abuse, an average of one in ten rounds of masternode mixing incurs a fee of .0001 DASH.
Enter a target value for Amount of Dash to keep mixed. This value provides a lower boundary on the final amount of funds to be mixed. Depending on how the client splits your wallet balance, you may end up with denominated inputs whose sum total is greater than the target amount. In this case the client will use all existing denominated inputs in the PrivateSend process. The final mixed amount may be higher than your target, but should be close.
Click OK to save settings.
PrivateSend is disabled by default when you open the wallet. It will only start after you set the number of rounds and number of Dash to mix under settings and click Start Mixing on the Overview tab of your wallet.
The PrivateSend process is initiated by clicking the Start Mixing button on the Overview tab of the Dash Core wallet. Mixing is possible once the following conditions have been met:
- The wallet contains sufficient non-mixed funds to create the minimum required denominated values
- The user has not disabled PrivateSend in the Options dialog
- The target value for mixed Funds in the Options dialog is greater than zero
If your wallet is encrypted (highly recommended), you will be asked to enter your wallet passphrase. Enable the Only for mixing via PrivateSend checkbox to unlock the wallet for mixing only.
This will unlock your wallet, and the PrivateSend mixing process will begin. The wallet will remain unlocked until PrivateSend mixing is complete, at which point it will be locked automatically.
PrivateSend will begin creating transactions and your PrivateSend balance will gradually increase. This process can take some time, so be patient. You can monitor the process in more detail as described in the following section.
Any of the following actions will interrupt the mixing process. Because the transactions are atomic (they either take place completely, or do not take place at all), it should be possible to safely interrupt PrivateSend mixing at any time.
- Clicking the Stop Mixing button on the Overview tab
- Closing the client before PrivateSend mixing is completed
- Sending PrivateSend funds from the wallet before PrivateSend rounds are completed
- Disabling PrivateSend before the process is complete
If you want to monitor PrivateSend in more detail, you need to enable some advanced features of the wallet. Go to Settings, select Options and go to the Wallet tab. Check the boxes next to the Enable coin control features and Enable advanced PrivateSend interface options.
This will allow you to monitor progress and see which individual operations PrivateSend is carrying out in the background.
Since PrivateSend mixing creates a lot of new address keys to send and receive the mixed denominations, you may receive a warning when the number of remaining keys runs low. This is nothing to be worried about, since the wallet will simply create more keys as necessary. However, these keys will not exist in any previous backups of your wallet. For this reason, it is important to backup your wallet again after mixing is complete.
You can also monitor PrivateSend progress by viewing the transactions created by the mixing process on the Transactions tab.
The following table describes the PrivateSend-related transactions displayed in the Type column of the Transactions tab:
|PrivateSend Transaction Type||Transaction Description|
|PrivateSend Make Collateral Inputs (Mixing)||Wallet funds were moved to collateral inputs that will be used to make collateral payments. This is done to minimize traceability of collaterals.|
|PrivateSend Create Denominations (Mixing)||Wallet funds were broken into PrivateSend denominations (Step 1 here)|
|PrivateSend Denominate (Mixing)||A transaction was sent to a masternode in order to participate in a mixing session (Step 3 here)|
|PrivateSend Collateral Payment (Mixing)||The mixing session collateral was claimed. This fee is charged in ~10% of mixing sessions to prevent spam attacks.|
|PrivateSend (Spending)||Mixed funds were used to send a payment to someone. Note: Unlike the previous 4 transaction types, this is not a mixing process transaction.|
You can also use the coin control feature to view which addresses hold mixed denominations ready to be used for PrivateSend transactions. Go to the Send tab of your wallet and click Inputs to view the possible input addresses for your transactions. You can see how each address holds given denominations of mixed Dash, and how many rounds of mixing have been completed. This is to ensure that an efficient combination of addresses can be used as inputs in PrivateSend transactions without too much change, since amount in a PrivateSend transaction must be rounded up to completely spend all inputs. The current minimum balance for an input used in a PrivateSend transaction is 0.00100010 DASH.
Paying with PrivateSend¶
You can only use PrivateSend for payments once you have mixed enough Dash to make up the amount you are trying to send. Because the mixing process takes time, it must be done in advance before you create the send transaction. A PrivateSend transaction is effectively the same as any other transaction on the blockchain, but it draws only from input addresses where the denomination has previously been mixed to ensure privacy of funds. Because several input addresses are usually required to make up the amount you are trying to send, a PrivateSend transaction will usually take up more space (in kilobytes) on the blockchain, and therefore will be charged a slightly higher fee.
To send a payment using PrivateSend, go to the Send tab of the Dash Core wallet and enable the PrivateSend option. The balance displayed will change to show your PrivateSend balance instead of the total balance. You can then enter the Pay To address, Label, Amount and click Send as usual. Your payment will be rounded up to completely spend the lowest possible denomination of mixed balance available (currently to the nearest 0.001 DASH). You will be prompted to enter your password and receive a detailed breakdown of the fee structure for PrivateSend before sending.
This documentation describes how to use InstantSend to instantly send funds to any other Dash user around the world. Dash InstantSend is supported by many wallets and vendors, including (but not limited to) the following:
- Dash Core Wallet
- Dash Android Wallet
- Dash iOS Wallet
- My Dash Wallet
- and many more...
You can read more about InstantSend theory and processes here.
Paying with InstantSend¶
InstantSend functions by setting a flag on the transaction, causing deterministic selection of a quorum of 10 masternodes for each input spent in an InstantSend transaction. The masternodes examine the input, and if a majority determines it has at least six confirmations, they then accept the transaction. The input is then locked until the transaction has been confirmed in six mined blocks, at which point the output can be used as an input in another InstantSend transaction. This differs from inputs used in normal transactions, which can be spent after just one confirmation regardless of whether the Dash was received using InstantSend or not. A higher fee will be charged for InstantSend transactions with more than four inputs, according to the fee schedule. Note that the receiving wallet must also be aware of InstantSend in order to be able to immediately continue with the transaction or display an appropriate notification that the transaction should be considered locked. If the receiving wallet is not aware of InstantSend, it will simply appear as a normal transaction and you will need to wait for standard block confirmations.
To pay with InstantSend, simply check the relevant checkbox in your app. The following screenshots indicate where this setting can be found in the Dash Core, iOS and Android wallets.