Dash Core's InstantSend feature provides a way to lock transaction inputs and enable secure, instantaneous transactions. The network automatically attempts to upgrade any qualifying transaction to InstantSend without a need for the sending wallet to explicitly request it.
- To qualify for InstantSend, each transaction input must meet at least one of the following criteria:
- Be locked by InstantSend
- Be in a block that has a ChainLock
- Have at least the number confirmations (block depth) indicated by the table below
|Mainnet||6 Blocks (normal transactions)|
100 Blocks (mining/masternode rewards)
|Testnet / Regtest / Devnet||2 Blocks|
Transition to Deterministic InstantSend lock
Protocol version 70220 implements DIP22 which adds the
isdlockmessage as a replacement for the
islockmessage. Once the transition is complete, the
islockmessage will be deprecated.
The introduction of the Long-Living Masternode Quorum feature in Dash Core 0.14 provided a foundation to scale InstantSend. The transaction input locking process (and resulting network traffic) now occurs only within the quorum. This minimizes network congestion since only the
islock message or
isdlock message produced by the locking process is relayed to the entire Dash network. This message contains all the information necessary to verify a successful transaction lock.
Spork 2 (
SPORK_2_INSTANTSEND_ENABLED) is used to manage InstantSend. Spork 2 enables or disables the entire InstantSend feature. As of Dash Core 0.17.0, it also can be used to limit locking to transactions found in blocks.
In the event of a sustained overload of InstantSend, the spork can be set to a value of
1. This mode enables a clean transition to fully disabling InstantSend without interfering with ChainLocks. In this mode masternodes will stop creating locks for new transactions when they enter the mempool and will only lock them once mined into a block. Once all existing locked transactions are mined into blocks, InstantSend can then be disabled by setting the spork value to
0 without disrupting ChainLocks.
Note: A transaction will not be included in the block template (from the
getblocktemplate RPC) unless it:
- Has been locked, or
- Has been in the mempool for >=10 minutes (
A miner may still include any transaction, but blocks containing only locked transactions (or ones older than the timeout) should achieve a ChainLock faster. This is desirable to miners since it prevents any blockchain reorganizations that might orphan their block.
|→||Client sends InstantSend transaction|
|LLMQ Signing Sessions||Quorums internally process locking|
|Quorum(s) responsible for the transaction's inputs lock the inputs via LLMQ signing sessions|
|Once all inputs are locked, the quorum responsible for the overall transaction creates the transaction lock (|
|LLMQ Results||Quorum results broadcast to the network|
|←||Quorum responds with lock inventory|
|→||Client requests lock message|
|←||Quorum responds with lock message|
Once a transaction lock is approved, the
instantlock field of various RPCs is set to
true (e.g. the
Updated 16 days ago