Prerequisites
Accounts are a very beginner-friendly topic. But to help you better understand this page, we recommend you first read through our Introduction to Parallax.Account types
Parallax has two account types:- Externally-owned account (EOA) – controlled by anyone with the private keys
- Contract account – a smart contract deployed to the network, controlled by code. Learn about smart contracts
- Receive, hold and send Laxes and tokens
- Interact with deployed smart contracts
Key differences
Externally-owned- Creating an account costs nothing
- Can initiate transactions
- Transactions between externally-owned accounts can only be Laxes/token transfers
- Made up of a cryptographic pair of keys: public and private keys that control account activities
- Creating a contract has a cost because you’re using network storage
- Can only send transactions in response to receiving a transaction
- Transactions from an external account to a contract account can trigger code, which can execute many different actions, such as transferring tokens or even creating a new contract
- Contract accounts don’t have private keys. Instead, they are controlled by the logic of the smart contract code
An account examined
Parallax accounts have four fields:nonce
– A counter that indicates the number of transactions sent from an externally-owned account or the number of contracts created by a contract account. Only one transaction with a given nonce can be executed for each account, protecting against replay attacks where signed transactions are repeatedly broadcast and re-executed.balance
– The number of wei owned by this address. Wei is a denomination of LAX and there are 1e+18 wei per Lax.codeHash
– This hash refers to the code of an account on the Parallax Virtual Machine (PVM). Contract accounts have code fragments programmed in that can perform different operations. This PVM code gets executed if the account gets a message call. It cannot be changed, unlike the other account fields. All such code fragments are contained in the state database under their corresponding hashes for later retrieval. This hash value is known as a codeHash. For externally owned accounts, the codeHash field is the hash of an empty string.storageRoot
– Sometimes known as a storage hash. A 256-bit hash of the root node of a Merkle Patricia trie that encodes the storage contents of the account (a mapping between 256-bit integer values), encoded into the trie as a mapping from the Keccak 256-bit hash of the 256-bit integer keys to the RLP-encoded 256-bit integer values. This trie encodes the hash of the storage contents of this account, and is empty by default.
Externally-owned accounts and key pairs
An account is made up of a cryptographic pair of keys: public and private. They help prove that a transaction was actually signed by the sender and prevent forgeries. Your private key is what you use to sign transactions, so it grants you custody over the funds associated with your account. You never really hold cryptocurrency, you hold private keys – the funds are always on Parallax’s ledger. This prevents malicious actors from broadcasting fake transactions because you can always verify the sender of a transaction. If Alice wants to send Laxes from her own account to Bob’s account, Alice needs to create a transaction request and send it out to the network for verification. Parallax’s usage of public-key cryptography ensures that Alice can prove that she originally initiated the transaction request. Without cryptographic mechanisms, a malicious adversary Eve could publicly broadcast a request that looks something like “send 5 Laxes from Alice’s account to Eve’s account,” and no one would be able to verify that it didn’t come from Alice.Account creation
When you want to create an account most libraries will generate you a random private key. A private key is made up of 64 hex characters and can be encrypted with a password. Example:fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd036415f
The public key is generated from the private key using the Elliptic Curve Digital Signature Algorithm↗. You get a public address for your account by taking the last 20 bytes of the Keccak-256 hash of the public key and adding 0x
to the beginning.
The following example shows how to use a signing tool called Clef to generate a new account. Clef is an account management and signing tool that comes bundled with the Parallax client. The clef newaccount
command creates a new key pair and saves them in an encrypted keystore.
Contract accounts
Contract accounts also have a 42 character hexadecimal address: Example:0x06012c8cf97bead5deae237070f9587f8e7a266d
The contract address is usually given when a contract is deployed to Parallax. The address comes from the creator’s address and the number of transactions sent from that address (the “nonce”).
A note on wallets
An account is not a wallet. An account is the keypair for a user-owned Parallax account. A wallet is an interface or application that lets you interact with your Parallax account.Further reading
- Understanding Ethereum Accounts↗ - etherscan