050_register_key.md

Register stake address in the blockchain

Before, we created our payment keys and address, which allow us to control our funds; we also created our stake keys and stake address, which allow us to participate in the protocol by delegating our stake or by creating a stake pool.

We need to register our stake key in the blockchain. To achieve this, we:

• Create a registration certificate
• Determine the Time-to-Live (TTL)
• Calculate the fees and deposit
• Submit the certificate to the blockchain with a transaction

Create a registration certificate:

cardano-cli shelley stake-address registration-certificate \
--stake-verification-key-file stake.vkey \
--out-file stake.cert

Once the certificate has been created, we must include it in a transaction to post it to the blockchain.

Determine the TTL

As before, to create the transaction you need to determine the TTL querying the tip and adding some slots to give you sufficient time to build the transaction.

Calculate fees and deposit

This transaction has only 1 input (the UTXO used to pay the transaction fee) and 1 output (our payment.addr to which we are sending the change). This transaction has to be signed by both the payment signing key payment.skey and the stake signing key stake.skey; and includes the certificate stake.cert:

cardano-cli shelley transaction calculate-min-fee \
--tx-in-count 1 \
--tx-out-count 1 \
--ttl 987654 \
--testnet-magic 42 \
--signing-key-file payment.skey \
--signing-key-file stake.skey \
--certificate-file stake.cert \
--protocol-params-file protocol.json

> 171485

In this transaction we have to not only pay transaction fees, but also include a deposit (which we will get back when we deregister the key) as stated in the protocol parameters:

The deposit amount can be found in the protocol.json under keyDeposit:

    ...
    "keyDeposit": 400000,
    ...

Query the UTXO:

    cardano-cli shelley query utxo \
        --address $(cat payment.addr) \
        --testnet-magic 42

    >                            TxHash                                 TxIx        Lovelace
    > ----------------------------------------------------------------------------------------
    > b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee     1      1000000000

So we have 1000 ada, calculate the change to send back to payment.addr:

expr 1000000000 - 171485 - 400000

> 999428515

Submit the certificate with a transaction:

Build the transaction:

cardano-cli shelley transaction build-raw \
--tx-in b64ae44e1195b04663ab863b62337e626c65b0c9855a9fbb9ef4458f81a6f5ee#1 \
--tx-out $(cat payment.addr)+999428515 \
--ttl 987654 \
--fee 171485 \
--out-file tx.raw \
--certificate-file stake.cert

Sign it:

cardano-cli shelley transaction sign \
--tx-body-file tx.raw \
--signing-key-file payment.skey \
--signing-key-file stake.skey \
--testnet-magic 42 \
--out-file tx.signed

And submit it:

cardano-cli shelley transaction submit \
--tx-file tx.signed \
--testnet-magic 42

Your stake key is now registered in the blockchain.