Last update: December 14, 2020

Creating and sending private transactions

Create and send private transactions using:

All private transaction participants must be online for a private transaction to be successfully distributed. If any participants are offline when submitting the private transaction, the transaction is not attempted and you must resubmit the transaction.

The gas and gasPrice specified when sending a private transaction are used by the privacy marker transaction not the private transaction itself.

Note

Private transactions either deploy contracts or call contract functions. Ether transfer transactions cannot be private.

`eea_sendRawTransaction`

eea_sendRawTransaction distributes the private transaction to the participating nodes, and signs and submits the privacy marker transaction, as described in Private Transaction Processing.

Note

If sending more than one transaction for mining in the same block (that is, you are not waiting for the transaction receipt), you must calculate the private transaction nonce outside Besu.

Use priv_getTransactionCount or priv_getEeaTransactionCount to get the nonce for an account for the specified privacy group or participants.

`priv_distributeRawTransaction`

priv_distributeRawTransaction distributes the private transaction to the participating nodes but does not sign and submit the privacy marker transaction. That is, priv_distributeRawTransaction performs steps 1 to 5 of Private Transaction Processing.

If using priv_distributeRawTransaction instead of eea_sendRawTransaction, use the value returned by priv_distributeRawTransaction, which is the enclave key to the private transaction in Orion, in the data field of a call to eth_sendRawTransaction.

By using the public Ethereum transaction, eth_sendRawTransaction, you are signing and submitting the privacy marker transaction yourself instead of having it signed by the Besu node, giving you greater control over the privacy marker transaction.

Use priv_distributeRawTransaction to send concurrent private transactions.

Warning

If the privacy marker transaction is not sent after distributing the private transaction, the distributed private transaction is not executed and the private states are not updated.

Example

Distribute private transaction using priv_distributeRawTransaction:

{
  "jsonrpc":"2.0",
  "method":"priv_distributeRawTransaction",
  "params":["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"],
  "id":1
}

Enclave key to the private transaction in Orion returned by priv_distributeRawTransaction:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0xfd0d90ab824574abc19c0776ca0210e764561d0ef6d621f2bbbea316eccfe56b"
}

Send the enclave key in the data field, and the privacy precompile address in the to field of eth_sendTransaction:

{
  "jsonrpc":"2.0",
  "method":"eth_sendTransaction",
  "params":[{
    "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",
    "to": "0x000000000000000000000000000000000000007e",
    "data": "0xfd0d90ab824574abc19c0776ca0210e764561d0ef6d621f2bbbea316eccfe56b",
    "gas": "0x2E1800",
    "gasPrice": "0x9184e72a000"
  }],
  "id":1
}

EEA-compliant or Besu-extended Privacy

To create an EEA-compliant private transaction, specify privateFor when creating the signed transaction passed as an input parameter to eea_sendRawTransaction.

To create a Besu-extended private transaction, specify a privacyGroupId when creating the signed transaction passed as an input parameter to eea_sendRawTransaction.

Unsigned and unencoded private transactions

The eea_sendRawTransaction parameter is a signed RLP-encoded private transaction. Shown below are examples of unsigned and unencoded private transactions to create a contract.

Unencoded and unsigned EEA-compliant private transaction

{
  "to": null,
  "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",
  "gas": "0x7600",
  "gasPrice": "0x0",
  "data": "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",
  "nonce": "0x0",
  "privateFrom": "negmDcN2P4ODpqn/6WkJ02zT/0w0bjhGpkZ8UP6vARk=",
  "privateFor": ["g59BmTeJIn7HIcnq8VQWgyh/pDbvbt2eyP0Ii60aDDw=","6fg8q5rWMBoAT2oIiU3tYJbk4b7oAr7dxaaVY7TeM3U="],
  "restriction": "restricted"
}

Unencoded and unsigned Besu-extended private transaction

{
  "to": null,
  "from": "0xfe3b557e8fb62b89f4916b721be55ceb828dbd73",
  "gas": "0x7600",
  "gasPrice": "0x0",
  "data": "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",
  "nonce": "0x0",
  "privateFrom": "negmDcN2P4ODpqn/6WkJ02zT/0w0bjhGpkZ8UP6vARk=",
  "privacyGroupId": "kAbelwaVW7okoEn1+okO+AbA4Hhz/7DaCOWVQz9nx5M=",
  "restriction": "restricted"
}

Tip

The example directory in the web3js-eea client library contains examples of signing and encoding private transactions.