# Account

A zkopru account manages both of the layer-1 and layer-2 key pairs. First of all, the account has an Ethereum account from a randomly generated private key. This is used for interactions on the layer-1. Second, Zkopru wallet creates a Babyjubjub private key and public key set from the Ethereum account's private key. This Babyjubjub keyset is used for the EdDSA and encrypted memo field on the layer-2.

| Key                     | Size               | How to get                          | Where to use                |
| ----------------------- | ------------------ | ----------------------------------- | --------------------------- |
| Master seed             | 32 byte            | Randomly generated                  | Recover keys                |
| Ethereum private key    | 32 byte            | Derived from master seed with BIP39 | Layer1 ECDSA                |
| Ethereum public address | 20 byte            | Derived from the private key        | Layer 1 interactions        |
| Babyjubjub private key  | 254 bit            | Derived from Ethereum private key   | Create EdDSA to spend UTXO  |
| Babyjubjub public key   | (254 bit, 254 bit) | Derived from Babyjubjub private key | Proving ownership of a UTXO |