CoinJoin Messages

The following network messages all help control the CoinJoin features built into Dash and facilitated by the masternode network.

Since the messages are all related to a single process, this diagram shows them sequentially numbered. The dssu message (not shown) is sent by the masternode in conjunction with some responses. For additional details, refer to the Developer Guide CoinJoin section.

dsa

The dsa message allows a node to join a CoinJoin pool. A collateral fee is required and may be forfeited if the client acts maliciously. The message operates in two ways:

1. When sent to a masternode without a current CoinJoin queue, it initiates the start of a new queue

2. When sent to a masternode with a current queue, it attempts to join the existing queue

Dash Core attempts to join an existing queue first and only requests a new one if no existing ones are available.

Bytes	Name	Data type	Required	Description
4	nDenom	int	Required	Denomination that will be exclusively used when submitting inputs into the pool
216+	txCollateral	tx message	Required	Collateral TX that will be charged if this client acts maliciously

The following annotated hexdump shows a dsa message. (The message header has been omitted.) Note that the 'Required inputs' bytes will only be preset if Spork 6 is active and protocol version => 70209.

Text

02000000 ................................... Denomination: 1 Dash (2)

Collateral Transaction
| Previous Output
| |
| | 010000000183bd1980c71c38f035db9b
| | 14d7f934f7d595181b3436e362899026 ....... Outpoint TXID
| | 19f3f7d3 ............................... Outpoint index number: 3556242201
|
| 83 ....................................... Bytes in sig. script: 131
|
| 000000006b483045022100f4d8fa0ae4132235fe
| cd540a62715ccfb1c9a97f8698d066656e30bb1e
| 1e06b90220301b4cc93f38950a69396ed89dfcc0
| 8e72ec8e6e7169463592a0bf504946d98b812102
| fa4b9c0f9e76e06d57c75cab9c8368a62a1ce8db
| 6eb0c25c3e0719ddd9ab549cffffffff01e09304
| 00000000001976a914f895 ................... Secp256k1 signature: None
|
| 6a4eb0e5 ................................. Sequence number: 3853536874

dsc

The dsc message indicates a CoinJoin session is complete.

Bytes	Name	Data type	Required	Description
4	nSessionID	int	Required	ID of the session
4	nMessageID	int	Required	ID of the message describing the result of the session

Reference the Message IDs table under the dssu message for descriptions of the Message ID values.

The following annotated hexdump shows a dsc message. (The message header has been omitted.)

Text

d9070700 ............................. Session ID: 791686
14000000 ............................. Message ID: MSG_SUCCESS (20)

dsf

The dsf message is sent by the masternode as the final transaction in a CoinJoin session. The masternode expects nodes in the session to respond with a dss message.

Bytes	Name	Data type	Required	Description
4	nSessionID	int	Required	ID of the session
#	txFinal	tx message	Required	Final transaction with unsigned inputs

The following annotated hexdump shows a dsf message. (The message header has been omitted.) Transaction inputs/outputs are only shown for a single node (compare with the dsi message and dss message hexdumps).

Text

86140c00 ............................. Session ID: 791686

Transaction Message
| 01000000 ................................. Version: 1
|
| 0f ......................................... Number of inputs: 15
|
| [...] ...................................... 5 transaction inputs omitted
|
| Transaction input #6
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 02000000 ................................. Outpoint index number: 0
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #7
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0f000000 ................................. Outpoint index number: 15
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #8
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0d000000 ................................. Outpoint index number: 13
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
|
| [...] ...................................... 7 more transaction inputs omitted
|
|
| 0f ......................................... Number of outputs: 15
|
| Transaction output #1
| | e8e4f50500000000 ......................... Duffs (1.00001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | 14826d7ba05cf76588a5503c03951dc9
| | | | 14c91b6c ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
|
| [...] ...................................... 3 transaction outputs omitted
|
|
| Transaction output #5
| | e8e4f50500000000 ......................... 100,001,000 Duffs (1.0001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | 426614716e94812d483bca32374f6ac8
| | | | cd121b0d ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
|
| [...] ...................................... 9 transaction outputs omitted
|
|
| Transaction output #15
| | e8e4f50500000000 ......................... 100,001,000 Duffs (1.0001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | f01197177de2358928196a543b2bbd97
| | | | 3c2ab002 ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
| 00000000 ................................... locktime: 0 (a block height)

dsi

The dsi message replies to a dsq message that has the Ready field set to 0x01. The dsi message contains user inputs for processing along with the outputs and a collateral. Once the masternode receives dsi messages from all members of the pool, it responds with a dsf message.

Bytes	Name	Data type	Required	Description
?	vecTxDSIn	CTxDSIn[]	Required	Vector of users inputs (CTxDSIn serialization is equal to CTxIn serialization)
216+	txCollateral	tx message	Required	Collateral transaction which is used to prevent misbehavior and also to charge fees randomly
?	vecTxDSOut	CTxDSOut[]	Required	Vector of user outputs (CTxDSOut serialization is equal to CTxOut serialization)

The following annotated hexdump shows a dsi message. (The message header has been omitted.)

Text

User inputs
| 03 ......................................... Number of inputs: 3
|
| Transaction input #1
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 02000000 ................................. Outpoint index number: 2
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #2
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0f000000 ................................. Outpoint index number: 15
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #3
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0d000000 ................................. Outpoint index number: 13
| |
| | 00 ....................................... Bytes in sig. script: 0
| | .......................................... Secp256k1 signature: None
| |
| | ffffffff ................................. Sequence number: UINT32_MAX

Collateral Transaction
| 01000000 ................................... Version: 1
|
| 01 ......................................... Number of inputs: 1
|
| Previous Output
| |
| | 83bd1980c71c38f035db9b14d7f934f7
| | d595181b3436e36289902619f3f7d383 ......... Outpoint TXID
| | 00000000 ................................. Outpoint index number: 0
| |
| | 6b ....................................... Bytes in sig. script: 107
| |
| | 483045022100f4d8fa0ae4132235fecd540a
| | 62715ccfb1c9a97f8698d066656e30bb1e1e
| | 06b90220301b4cc93f38950a69396ed89dfc
| | c08e72ec8e6e7169463592a0bf504946d98b
| | 812102fa4b9c0f9e76e06d57c75cab9c8368
| | a62a1ce8db6eb0c25c3e0719ddd9ab549c ....... Secp256k1 signature
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| 01 ......................................... Number of outputs: 1
|
| | e093040000000000 ......................... 300,000 Duffs (0.003 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | f8956a4eb0e53b05ee6b30edfd2770b5
| | | | 26c1f1bb ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
| 00000000 ................................... locktime: 0 (a block height)

User outputs
| 03 ......................................... Number of outputs: 3
|
| Transaction output #1
| | e8e4f50500000000 ......................... 100,001,000 Duffs (1.0001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | 14826d7ba05cf76588a5503c03951dc9
| | | | 14c91b6c ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
| Transaction output #2
| | e8e4f50500000000 ......................... 100,001,000 Duffs (1.0001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | f01197177de2358928196a543b2bbd97
| | | | 3c2ab002 ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
| Transaction output #3
| | e8e4f50500000000 ......................... 100,001,000 Duffs (1.0001 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | 426614716e94812d483bca32374f6ac8
| | | | cd121b0d ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG

dsq

The dsq message provides nodes with queue details and notifies them when to sign final transaction messages.

If the message indicates the queue is not ready, the node verifies the message is valid. It also verifies that the masternode is not flooding the network with dsq messages in an attempt to dominate the queuing process. It then relays the message to its connected peers.

If the message indicates the queue is ready, the node responds with a dsi message.

Bytes	Name	Data type	Required	Description
4	nDenom	int	Required	Denomination allowed in this session
36	masternodeOutPoint	outPoint	Required	The unspent outpoint of the masternode (holding 1000 DASH) which is hosting this session
8	nTime	int64_t	Required	Time this dsq message was created
1	fReady	bool	Required	Indicates if the pool is ready to be executed
97	vchSig	char[]	Required	ECDSA signature (65 bytes) prior to DIP3 activation BLS Signature of this message by masternode verifiable via pubKeyMasternode (Length (1 byte) + Signature (96 bytes))

Denominations (per src/coinjoin.cpp)

Value	Denomination
1	10 Dash
2	1 Dash
4	0.1 Dash
8	0.01 Dash
16	0.001 Dash

The following annotated hexdump shows a dsq message. (The message header has been omitted.) Note that the 'Required inputs' bytes will only be preset if Spork 6 is active and protocol version => 70209.

Text

01000000 ............................. Denomination: 10 Dash (1)

Masternode Outpoint
| a383a2489aedccfab4bb41368d1c8ee3
| 10d9ee90cb3d181880ce4e0cdb36ecb7
| 0f000000 ........................... Outpoint index number: 15

10b4235c00000000 ..................... Create Time: 2018-12-26 17:02:08 UTC

00 ................................... Ready: 0

60 ................................... Signature length: 96

0409a1349869a02e90e6e1f6d92bf995
27a72542fed987f6d2719596973d89e6
74605a3585b1335650f1555f7576061d
110fb72b3308e378ac8e8fbebeeffdb4
9b2a6562ad965bb3c3fd3f8e68483fdb
0d1401e2264071a74fc01d51e943ce9f ..... Masternode BLS Signature

dss

The dss message replies to a dsf message sent by the masternode managing the session. The dsf message provides the unsigned transaction inputs for all members of the pool. Each node verifies that the final transaction matches what is expected. They then sign any transaction inputs belonging to them and then relay them to the masternode via this dss message.

Once the masternode receives and validates all dss messages, it issues a dsc message. If a node does not respond to a dsf message with signed transaction inputs, it may forfeit the collateral it provided. This is to minimize malicious behavior.

Bytes	Name	Data type	Required	Description
#	inputs	txIn[]	Required	Signed inputs for the session

The following annotated hexdump shows a dss message. (The message header has been omitted.) Note that these will be the same transaction inputs that were supplied (unsiged) in the dsi message.

Text

User inputs
| 03 ......................................... Number of inputs: 3
|
| Transaction input #1
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 02000000 ................................. Outpoint index number: 2
| |
| | 6b ....................................... Bytes in sig. script: 107
| | 483045022100b3a861dca83463aabf5e4a14a286
| | 1b9c2e51e0dedd8a13552e118bf74eb4a68d0220
| | 4a91c416768d27e6bdcfa45d28129841dbcc728b
| | f0bbec9701cfc4e743d23adf812102cc4876c9da
| | 84417dec37924e0479205ce02529bb0ba88631d3
| | ccc9cfcdf00173 ........................... Secp256k1 signature
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #2
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0f000000 ................................. Outpoint index number: 15
| |
| | 6a ....................................... Bytes in sig. script: 106
| | 4730440220268f3b7799ca4ec132e511a4756019
| | c56016f7771561dc0597d84e9b1fa9fc08022067
| | 5199b9b3f9a7eba69b7bbb4aa2a413d955762f9d
| | 68be5a9c02c6772c8078fd812103258925f0dbbf
| | 9d5aa20a675459fa2e86c9f9061dee82a00dca73
| | 9080f051d891 ............................. Secp256k1 signature
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| Transaction input #3
| |
| | 36bdc3796c5630225f2c86c946e2221a
| | 9958378f5d08da380895c2656730b5c0 ......... Outpoint TXID
| | 0d000000 ................................. Outpoint index number: 13
| |
| | 6a ....................................... Bytes in sig. script: 106
| | 4730440220404bb067e0c94a2bd75c6798c1af8c
| | 95e8b92f5e437cff2bcb4660f24a34d06d02203a
| | b707bd371a84a9e7bd1fbe3b0c939fd23e0a9165
| | de78809b9310372a4b3879812103a9a6c5204811
| | a8cab04b595ed622a1fed6efd3b2d888fadd0c97
| | 3737fcdf2bc7 ............................. Secp256k1 signature
| |
| | ffffffff ................................. Sequence number: UINT32_MAX

dssu

The dssu message provides a pool status update.

Bytes	Name	Data type	Required	Description
4	nMsgSessionID	int	Required	Session ID
4	nMsgState	int	Required	Current state of processing
4	nMsgEntriesCount	int	Required	Deprecated in Dash Core 0.15.0 Number of entries in the pool
4	nMsgStatusUpdate	int	Required	Update state and/or signal if entry was accepted or not
4	nMsgMessageID	int	Required	ID of the typical masternode reply message

Pool State

State	Description
0	POOL_STATE_IDLE
1	POOL_STATE_QUEUE
2	POOL_STATE_ACCEPTING_ENTRIES
3	POOL_STATE_SIGNING
4	POOL_STATE_ERROR
5	POOL_STATE_SUCCESS Deprecated in Dash Core 0.16.0

Pool Status Update

Status	Description
0	STATUS_REJECTED
1	STATUS_ACCEPTED

Message IDs

Code	Description
0x00	ERR_ALREADY_HAVE
0x01	ERR_DENOM
0x02	ERR_ENTRIES_FULL
0x03	ERR_EXISTING_TX
0x04	ERR_FEES
0x05	ERR_INVALID_COLLATERAL
0x06	ERR_INVALID_INPUT
0x07	ERR_INVALID_SCRIPT
0x08	ERR_INVALID_TX
0x09	ERR_MAXIMUM
0x0A (10)	ERR_MN_LIST
0x0B (11)	ERR_MODE
0x0C (12)	ERR_NON_STANDARD_PUBKEY (Not used)
0x0D (13)	ERR_NOT_A_MN (Not used)
0x0E (14)	ERR_QUEUE_FULL
0x0F (15)	ERR_RECENT
0x10 (16)	ERR_SESSION
0x11 (17)	ERR_MISSING_TX
0x12 (18)	ERR_VERSION
0x13 (19)	MSG_NOERR
0x14 (20)	MSG_SUCCESS
0x15 (21)	MSG_ENTRIES_ADDED
0x16 (22)	ERR_SIZE_MISMATCH

The following annotated hexdump shows a dssu message. (The message header has been omitted.)

Text

86140c00 ............................. Session ID: 791686
02000000 ............................. State: POOL_STATE_ACCEPTING_ENTRIES (2)
01000000 ............................. Status Update: STATUS_ACCEPTED (1)
13000000 ............................. Message ID: MSG_NOERR (0x13)

dstx

The dstx message allows masternodes to broadcast subsidized transactions without fees (to provide security in processing).

Bytes	Name	Data type	Required	Description
#	tx	tx message	Required	The transaction
36	masternode OutPoint	outPoint	Required	The unspent outpoint of the masternode (holding 1000 DASH) which is signing the message
97	vchSig	char[]	Required	ECDSA signature (65 bytes) prior to DIP3 activation BLS Signature of this message by masternode verifiable via pubKeyMasternode (Length (1 byte) + Signature (96 bytes))
8	sigTime	int64_t	Require	Time this message was signed

The following annotated hexdump shows a dstx message. (The message header has been omitted.)

Text

Transaction Message
| 0200 ....................................... Version: 2
| 0000 ....................................... Type: 0 (Classical Tx)
|
| 05 ......................................... Number of inputs: 5
|
| Transaction input #1
| |
| | 0adb782b2170018eada54534be880e70
| | 74ed8307a566731119b1782362af43ad ......... Outpoint TXID
| | 05000000 ................................. Outpoint index number: 5
| |
| | 6b ....................................... Bytes in sig. script: 107
| | 483045022100b1243fcba562a0f1d7c4
| | cc3b320645dfa96c6412f368ccdbc1b7
| | acb6b0aa1db502201606c81b0d79f52f
| | 47bcb071b64c37f72dd1378efa67a2de
| | dd86c44d393668fa812102d6ff581270
| | 632f5e972b0418ee871867b5c04b6eae
| | 3458ad135ad8f1daaa4fc2 ................... Secp256k1 signature
| |
| | ffffffff ................................. Sequence number: UINT32_MAX
|
| [...] ...................................... 4 more transaction inputs omitted
|
|
| 05 ......................................... Number of outputs: 5
|
| Transaction output #1
| | 10f19a3b00000000 ......................... Duffs (10.0001000 Dash)
| |
| | 19 ....................................... Bytes in pubkey script: 25
| | | 76 ..................................... OP_DUP
| | | a9 ..................................... OP_HASH160
| | | 14 ..................................... Push 20 bytes as data
| | | | 3eb7ae776b096231de9eca42dd57a677
| | | | d3b05452 ............................. PubKey hash
| | | 88 ..................................... OP_EQUALVERIFY
| | | ac ..................................... OP_CHECKSIG
|
| [...] ...................................... 4 more transaction outputs omitted
|
|
| 00000000 ................................... locktime: 0 (a block height)

Masternode Unspent Outpoint
| ccfbe4e7c220264cb0a8bfa5e91c6957
| 33c255384790e80e891a0d8f56a59d9e ......... Outpoint TXID
| 01000000 ................................. Outpoint index number: 1

60 ......................................... Signature length: 96

94c8e427f448789f58cda17445e76c64
d0efa7c089addcb378f9b8d04b72f499
a4e8e616b5011886b9cffcce29e17fc1
10ad8609c3ee1a3207b882e7ff58400f
42d6e6544108b349da2cc5e716a5f266
4a2dc96b0f080effd5349f2ae06ac234 .......... Masternode Signature

59b4235c00000000 .......................... Sig Time: 2018-12-26 17:03:21 UTC