# UTXO

UTXOs include the following properties.

| Property                 | Description                                                                                 |
| ------------------------ | ------------------------------------------------------------------------------------------- |
| Ether                    | The amount of ETH                                                                           |
| Public Key               | A Babyjubjub point of the note owner                                                        |
| Salt                     | Random salt. Zkopru generates UTXO hash using this salt.                                    |
| Token Address (Optional) | The address of the token contract when it includes ERC20 or ERC721. The default value is 0. |
| ERC20 Amount (Optional)  | The amount of the ERC20 token when it includes ERC20. The default value is 0.               |
| NFT Id (Optional)        | The id of the ERC721 token when it includes ERC721. The default value is 0.                 |

And then Zkopru computes the leaf hash with Poseidon hash:

```javascript
var intermediate_hash = poseidon(ether, pub_key.x, pub_key.y, salt)
var result_hash = poseidon(intemediate_hash, token_address, erc20, nft)
```