Encoding & Signing

After every field of a transaction is prepared, following steps are required before it can be sent to network (don't worry, these steps are already implemented by wallets or SDKs):

1. Prepare hash for signing: do RLP encoding in the order of [nonce, gasPrice, gas, to, value, storageLimit, epochHeight, chainId, data] and then apply the keccak256 operation to the encoded result to obtain a hash.
2. Signing: sign the hash obtained in the previous step using the private key of the sending account and perform the ecdsaSign signature operation to obtain the values for r, s, v.
3. Transaction Encoding: Do RLP encoding in the order of [[nonce, gasPrice, gas, to, value, storageLimit, epochHeight, chainId, data], v, r, s] and convert it into a hexadecimal string.

Broadcast to the network

After completing the above steps, you will obtain a hex-encoded rawTx. You can then use the cfx_sendRawTransaction method to send it to the network. Upon a successful invocation of this method, a transaction hash will be returned, which can be used to query the status of the transaction.

Referencia

• Elliptic Curve Digital Signature Algorithm (ECDSA)
• keccak256 hashing
• Recursive Length Prefix (RLP) serialization