YouTube Video https://youtu.be/OI7oT9Knnlc Speaker Craig Drabik | Technical Lead | TxMQ, Inc. Abstract Hedera Cryptocurrency is a Hedera Hashgraph platform service that allows decentralized application developers to pay for services on the Hedera public network. With the Hedera API, developers can pay node fees, service fees, and transaction fees required by their dapp, as well as incorporate the Hedera cryptocurrency into their dapp. Due to expert efficiency and low fees, Hedera Hashgraph is the first DLT to make cryptocurrency microtransactions practical. In this session, Craig Drabik, Technical Lead at TxMQ, Inc., will take a deep dive into the Hedera API from a cryptocurrency perspective, conduct live API demonstrations, and talk real-world use cases.

1. CraigDrabik
Technical Lead

2. Hedera API: Cryptocurrency 101

3. OVERVIEW
Roles that cryptocurrency plays on Hedera
Basic Concepts: Transaction Lifecycle,
Accounts, Keys, Signatures
Hedera Cryptocurrency API Services
Hedera Cryptocurrency Goodies

4. Why Does Hedera Need a Cryptocurrency?

5. Security
Why Crypto?
Cryptocurrency has an important role
in securing the network by providing
economic barriers to certain kinds of
attacks and disruptions
• Nodes must be staked, and nodes’
votes are weighted by stake
• Fees for transactions discourage
transaction-based attacks
• Encourages efficient use of
resources by DApps
6

6. Incentivize
Participation
Why Crypto?
Network participants provide computing
resources to anyone with a key pair. The
survival of the network relies on the
ongoing operation of each node.
• Node Fees: Nodes receive payments
from clients for transactions they
submit to the network
• Network Fees: Nodes receive incentive
payments for participating in consensus
• Service Fees: Nodes receive payments
for services such as storing files or
executing smart contracts

7. Micropayments
Why Crypto? Hedera payments are fast, secure,
and very low cost
• Fees for services can be very small,
on the order of fractions of a cent
• There are no banking, credit card,
or 3rd party fees.
• Transfers are instantaneous
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8. Basic Hedera Concepts

9. •Accounts
•Keys and Signatures
•Transaction Lifecycle
Building Blocks
Hedera
Cryptocurrency

10. A Hedera account is:
• An identifier
• The key or keys associated with an account
• Thresholds for:
‣ When a record is automatically generated
‣ When the recipient of a transfer must counter-sign
• Auto-renew period
Hedera
Accounts

11. Hedera
Keys
Hedera keys can be..
• ECDSA384, RSA3072, or ED25519 format keys
• A smart contract can act as a key
• A key list
• A “threshold key list”
• A nested structure of the above*

12. Hedera
Signatures
Hedera natively supports multi-sig. Signatures must
match the account’s key structure
• Transactions for a single-key account must be
signed by that key
• Transactions for a list of keys must be signed by all
keys in the list
• Transactions for a threshold key list must be signed
by enough keys in the list
• Signatures for nested key structures must match
the key structure

13. Hedera Transaction Lifecycle

14. Hedera Cryptocurrency API

15. Hedera
Cryptocurrency
API Operations
• Create or delete an account
• Update account information
• Transfer funds
• Proxy stake
• Claims

16. Hedera API:
Account Transactions
To create a Hedera account..
• The account must be created
and funded by another account
• The account number is
generated by the network
• The account is associated with
a shard and realm

17. Hedera API:
Account Transactions
To delete a Hedera account..
• The delete is a “soft delete”
• The account isn’t destroyed until
it can no longer auto-renew
• The ability to generate a record
containing a state proof requires
the account to continue to exist
for a certain period of time

18. Demo: Create an Account

19. Hedera API:
Crypto Transactions
• Get account balance
• Transfer funds
• Add or revoke claims

20. Hedera API:
Transfer Lists
Transfers on Hedera have the
ability to bundle multiple payers
and payees in a single transfer
transaction
• Limited to 10 accounts*
• Can include payers and payees in
any combination
• Must be zero-sum

21. Demo: Transfer Funds

22. Use Case: Corporate Acquisition

23. Hedera
API
How to sell a company on Hedera
Consider a scenario where Hooli has entered into
negotiations to purchase Pied Piper. Both companies
have agreed to use Hedera to document that both
companies agree to the sale, and to make payment.
• Pied Piper is a small company, but the sale still needs a
majority of the business leaders to agree to the sale
• Hooli is a big company, and the acquisition must have
sign-off from the CEO, finance, risk, and the board

24. Hedera
API
How to sell a company on Hedera
Pied Piper’s signature requirement can be
modeled using a threshold key list.
• Pied Piper sets up an account on Hedera.
Richard, Monica, Jared, Dinesh, and Gilfoyle
all supply their public keys for the list.
• Three of the five must sign in order for the
sale to continue.

25. Hedera
API
How to sell a company on Hedera
Hooli’s situation is more complicated. The CEO and CFO
must agree individually, the board needs a majority vote,
and risk requires the unanimous approval of their
leadership to approve the acquisition.
•At the top level, we use a key list that requires signatures
from every key in the list.
•The CEO and CFO keys are traditional
single-party keys
•Risk’s key is itself a key list that requires
signatures from every key in the list
•The board’s key is itself a threshold key list
that requires signatures from a majority
of board members

26. Hedera
API
How to sell a company on Hedera
Both sides must produce valid signatures that
match the accounts’ specific structures or the
transaction will be rejected by the network.
Payment will only be made if…
•Three of Richard, Monica, Jared, Dinesh, and
Gilfoyle must sign AND
•Gavin must sign AND
•Hooli’s CFO must sign AND
•Every risk leader must sign AND
•A majority of the Hooli board must sign
…otherwise the transaction will be rejected by the
network and funds will not be transferred

27. Questions